JOSE Working Group M. Jones
Internet-Draft Microsoft
Intended status: Standards Track E. Rescorla
Expires: September 4, 2014 RTFM
J. Hildebrand
Cisco
March 3, 2014

JSON Web Encryption (JWE)
draft-ietf-jose-json-web-encryption-23

Abstract

JSON Web Encryption (JWE) represents encrypted content using JavaScript Object Notation (JSON) based data structures. Cryptographic algorithms and identifiers for use with this specification are described in the separate JSON Web Algorithms (JWA) specification and IANA registries defined by that specification. Related digital signature and MAC capabilities are described in the separate JSON Web Signature (JWS) specification.

Status of This Memo

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This Internet-Draft will expire on September 4, 2014.

Copyright Notice

Copyright (c) 2014 IETF Trust and the persons identified as the document authors. All rights reserved.

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Table of Contents

1. Introduction

JSON Web Encryption (JWE) represents encrypted content using JavaScript Object Notation (JSON) [RFC7158] based data structures. The JWE cryptographic mechanisms encrypt and provide integrity protection for an arbitrary sequence of octets.

Two closely related serializations for JWE objects are defined. The JWE Compact Serialization is a compact, URL-safe representation intended for space constrained environments such as HTTP Authorization headers and URI query parameters. The JWE JSON Serialization represents JWE objects as JSON objects and enables the same content to be encrypted to multiple parties. Both share the same cryptographic underpinnings.

Cryptographic algorithms and identifiers for use with this specification are described in the separate JSON Web Algorithms (JWA) [JWA] specification and IANA registries defined by that specification. Related digital signature and MAC capabilities are described in the separate JSON Web Signature (JWS) [JWS] specification.

Names defined by this specification are short because a core goal is for the resulting representations to be compact.

1.1. Notational Conventions

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in Key words for use in RFCs to Indicate Requirement Levels [RFC2119]. If these words are used without being spelled in uppercase then they are to be interpreted with their normal natural language meanings.

BASE64URL(OCTETS) denotes the base64url encoding of OCTETS, per Section 2.

UTF8(STRING) denotes the octets of the UTF-8 [RFC3629] representation of STRING.

ASCII(STRING) denotes the octets of the ASCII [USASCII] representation of STRING.

The concatenation of two values A and B is denoted as A || B.

2. Terminology

These terms defined by the JSON Web Signature (JWS) [JWS] specification are incorporated into this specification: "JSON Web Signature (JWS)", "Base64url Encoding", "Collision-Resistant Name", and "StringOrURI".

These terms are defined for use by this specification:

JSON Web Encryption (JWE)

A data structure representing an encrypted and integrity protected message.
Authenticated Encryption with Associated Data (AEAD)

An AEAD algorithm is one that encrypts the Plaintext, allows Additional Authenticated Data to be specified, and provides an integrated content integrity check over the Ciphertext and Additional Authenticated Data. AEAD algorithms accept two inputs, the Plaintext and the Additional Authenticated Data value, and produce two outputs, the Ciphertext and the Authentication Tag value. AES Galois/Counter Mode (GCM) is one such algorithm.
Plaintext

The sequence of octets to be encrypted -- a.k.a., the message. The plaintext can contain an arbitrary sequence of octets.
Ciphertext

An encrypted representation of the Plaintext.
Additional Authenticated Data (AAD)

An input to an AEAD operation that is integrity protected but not encrypted.
Authentication Tag

An output of an AEAD operation that ensures the integrity of the Ciphertext and the Additional Authenticated Data. Note that some algorithms may not use an Authentication Tag, in which case this value is the empty octet sequence.
Content Encryption Key (CEK)

A symmetric key for the AEAD algorithm used to encrypt the Plaintext for the recipient to produce the Ciphertext and the Authentication Tag.
JWE Header

JSON object containing the parameters describing the cryptographic operations and parameters employed. The JWE Header members are the union of the members of the JWE Protected Header, the JWE Shared Unprotected Header, and the JWE Per-Recipient Unprotected Header. The members of the JWE Header are Header Parameters.
JWE Encrypted Key

Encrypted Content Encryption Key (CEK) value. Note that for some algorithms, the JWE Encrypted Key value is specified as being the empty octet sequence.
JWE Initialization Vector

Initialization Vector value used when encrypting the plaintext. Note that some algorithms may not use an Initialization Vector, in which case this value is the empty octet sequence.
JWE AAD

Additional value to be integrity protected by the authenticated encryption operation. This can only be present when using the JWE JSON Serialization. (Note that this can also be achieved when using either serialization by including the AAD value as an integrity protected Header Parameter value, but at the cost of the value being double base64url encoded.)
JWE Ciphertext

Ciphertext value resulting from authenticated encryption of the plaintext with additional associated data.
JWE Authentication Tag

Authentication Tag value resulting from authenticated encryption of the plaintext with additional associated data.
Header Parameter

A name/value pair that is member of the JWE Header.
JWE Protected Header

JSON object that contains the JWE Header Parameters that are integrity protected by the authenticated encryption operation. These parameters apply to all recipients of the JWE. For the JWE Compact Serialization, this comprises the entire JWE Header. For the JWE JSON Serialization, this is one component of the JWE Header.
JWE Shared Unprotected Header

JSON object that contains the JWE Header Parameters that apply to all recipients of the JWE that are not integrity protected. This can only be present when using the JWE JSON Serialization.
JWE Per-Recipient Unprotected Header

JSON object that contains JWE Header Parameters that apply to a single recipient of the JWE. These Header Parameter values are not integrity protected. This can only be present when using the JWE JSON Serialization.
JWE Compact Serialization

A representation of the JWE as a compact, URL-safe string.
JWE JSON Serialization

A representation of the JWE as a JSON object. The JWE JSON Serialization enables the same content to be encrypted to multiple parties. This representation is neither optimized for compactness nor URL-safe.
Key Management Mode

A method of determining the Content Encryption Key (CEK) value to use. Each algorithm used for determining the CEK value uses a specific Key Management Mode. Key Management Modes employed by this specification are Key Encryption, Key Wrapping, Direct Key Agreement, Key Agreement with Key Wrapping, and Direct Encryption.
Key Encryption

A Key Management Mode in which the Content Encryption Key (CEK) value is encrypted to the intended recipient using an asymmetric encryption algorithm.
Key Wrapping

A Key Management Mode in which the Content Encryption Key (CEK) value is encrypted to the intended recipient using a symmetric key wrapping algorithm.
Direct Key Agreement

A Key Management Mode in which a key agreement algorithm is used to agree upon the Content Encryption Key (CEK) value.
Key Agreement with Key Wrapping

A Key Management Mode in which a key agreement algorithm is used to agree upon a symmetric key used to encrypt the Content Encryption Key (CEK) value to the intended recipient using a symmetric key wrapping algorithm.
Direct Encryption

A Key Management Mode in which the Content Encryption Key (CEK) value used is the secret symmetric key value shared between the parties.

3. JSON Web Encryption (JWE) Overview

JWE represents encrypted content using JSON data structures and base64url encoding. A JWE represents these logical values:

JWE Header

JSON object containing the parameters describing the cryptographic operations and parameters employed. The JWE Header members are the union of the members of the JWE Protected Header, the JWE Shared Unprotected Header, and the JWE Per-Recipient Unprotected Header, as described below.
JWE Encrypted Key

Encrypted Content Encryption Key (CEK) value.
JWE Initialization Vector

Initialization Vector value used when encrypting the plaintext.
JWE AAD

Additional value to be integrity protected by the authenticated encryption operation.
JWE Ciphertext

Ciphertext value resulting from authenticated encryption of the plaintext with additional associated data.
JWE Authentication Tag

Authentication Tag value resulting from authenticated encryption of the plaintext with additional associated data.

The JWE Header represents the combination of these logical values:

JWE Protected Header

JSON object that contains the JWE Header Parameters that are integrity protected by the authenticated encryption operation. These parameters apply to all recipients of the JWE.
JWE Shared Unprotected Header

JSON object that contains the JWE Header Parameters that apply to all recipients of the JWE that are not integrity protected.
JWE Per-Recipient Unprotected Header

JSON object that contains JWE Header Parameters that apply to a single recipient of the JWE. These Header Parameter values are not integrity protected.

This document defines two serializations for JWE objects: a compact, URL-safe serialization called the JWE Compact Serialization and a JSON serialization called the JWE JSON Serialization. In both serializations, the JWE Protected Header, JWE Encrypted Key, JWE Initialization Vector, JWE Ciphertext, and JWE Authentication Tag are base64url encoded for transmission, since JSON lacks a way to directly represent octet sequences. When present, the JWE AAD is also base64url encoded for transmission.

In the JWE Compact Serialization, no JWE Shared Unprotected Header or JWE Per-Recipient Unprotected Header are used. In this case, the JWE Header and the JWE Protected Header are the same.

In the JWE Compact Serialization, a JWE object is represented as the combination of these five string values,

In the JWE JSON Serialization, one or more of the JWE Protected Header, JWE Shared Unprotected Header, and JWE Per-Recipient Unprotected Header MUST be present. In this case, the members of the JWE Header are the combination of the members of the JWE Protected Header, JWE Shared Unprotected Header, and JWE Per-Recipient Unprotected Header values that are present.

In the JWE JSON Serialization, a JWE object is represented as the combination of these eight values, Section 7.2 for more information about the JWE JSON Serialization.

JWE utilizes authenticated encryption to ensure the confidentiality and integrity of the Plaintext and the integrity of the JWE Protected Header and the JWE AAD.

3.1. Example JWE

This example encrypts the plaintext "The true sign of intelligence is not knowledge but imagination." to the recipient using RSAES OAEP for key encryption and AES GCM for content encryption.

The following example JWE Protected Header declares that:

  {"alg":"RSA-OAEP","enc":"A256GCM"}

Encoding this JWE Protected Header as BASE64URL(UTF8(JWE Protected Header)) gives this value:

  eyJhbGciOiJSU0EtT0FFUCIsImVuYyI6IkEyNTZHQ00ifQ

The remaining steps to finish creating this JWE are:

The final result in this example (with line breaks for display purposes only) is:

  eyJhbGciOiJSU0EtT0FFUCIsImVuYyI6IkEyNTZHQ00ifQ.
  OKOawDo13gRp2ojaHV7LFpZcgV7T6DVZKTyKOMTYUmKoTCVJRgckCL9kiMT03JGe
  ipsEdY3mx_etLbbWSrFr05kLzcSr4qKAq7YN7e9jwQRb23nfa6c9d-StnImGyFDb
  Sv04uVuxIp5Zms1gNxKKK2Da14B8S4rzVRltdYwam_lDp5XnZAYpQdb76FdIKLaV
  mqgfwX7XWRxv2322i-vDxRfqNzo_tETKzpVLzfiwQyeyPGLBIO56YJ7eObdv0je8
  1860ppamavo35UgoRdbYaBcoh9QcfylQr66oc6vFWXRcZ_ZT2LawVCWTIy3brGPi
  6UklfCpIMfIjf7iGdXKHzg.
  48V1_ALb6US04U3b.
  5eym8TW_c8SuK0ltJ3rpYIzOeDQz7TALvtu6UG9oMo4vpzs9tX_EFShS8iB7j6ji
  SdiwkIr3ajwQzaBtQD_A.
  XFBoMYUZodetZdvTiFvSkQ

See Appendix A.1 for the complete details of computing this JWE. See other parts of Appendix A for additional examples.

4. JWE Header

The members of the JSON object(s) representing the JWE Header describe the encryption applied to the Plaintext and optionally additional properties of the JWE. The Header Parameter names within the JWE Header MUST be unique; recipients MUST either reject JWEs with duplicate Header Parameter names or use a JSON parser that returns only the lexically last duplicate member name, as specified in Section 15.12 (The JSON Object) of ECMAScript 5.1 [ECMAScript].

Implementations are required to understand the specific Header Parameters defined by this specification that are designated as "MUST be understood" and process them in the manner defined in this specification. All other Header Parameters defined by this specification that are not so designated MUST be ignored when not understood. Unless listed as a critical Header Parameter, per Section 4.1.12, all Header Parameters not defined by this specification MUST be ignored when not understood.

There are three classes of Header Parameter names: Registered Header Parameter names, Public Header Parameter names, and Private Header Parameter names.

4.1. Registered Header Parameter Names

The following Header Parameter names are registered in the IANA JSON Web Signature and Encryption Header Parameters registry defined in [JWS], with meanings as defined below.

As indicated by the common registry, JWSs and JWEs share a common Header Parameter space; when a parameter is used by both specifications, its usage must be compatible between the specifications.

4.1.1. "alg" (Algorithm) Header Parameter

This parameter has the same meaning, syntax, and processing rules as the alg Header Parameter defined in Section 4.1.1 of [JWS], except that the Header Parameter identifies the cryptographic algorithm used to encrypt or determine the value of the Content Encryption Key (CEK). The encrypted content is not usable if the alg value does not represent a supported algorithm, or if the recipient does not have a key that can be used with that algorithm.

A list of defined alg values for this use can be found in the IANA JSON Web Signature and Encryption Algorithms registry defined in [JWA]; the initial contents of this registry are the values defined in Section 4.1 of the JSON Web Algorithms (JWA) [JWA] specification.

4.1.2. "enc" (Encryption Algorithm) Header Parameter

The enc (encryption algorithm) Header Parameter identifies the content encryption algorithm used to encrypt the Plaintext to produce the Ciphertext. This algorithm MUST be an AEAD algorithm with a specified key length. The recipient MUST reject the JWE if the enc value does not represent a supported algorithm. enc values should either be registered in the IANA JSON Web Signature and Encryption Algorithms registry defined in [JWA] or be a value that contains a Collision-Resistant Name. The enc value is a case-sensitive string containing a StringOrURI value. This Header Parameter MUST be present and MUST be understood and processed by implementations.

A list of defined enc values for this use can be found in the IANA JSON Web Signature and Encryption Algorithms registry defined in [JWA]; the initial contents of this registry are the values defined in Section 5.1 of the JSON Web Algorithms (JWA) [JWA] specification.

4.1.3. "zip" (Compression Algorithm) Header Parameter

The zip (compression algorithm) applied to the Plaintext before encryption, if any. The zip value defined by this specification is: [JWA]. The zip value is a case-sensitive string. If no zip parameter is present, no compression is applied to the Plaintext before encryption. This Header Parameter MUST be integrity protected, and therefore MUST occur only within the JWE Protected Header, when used. Use of this Header Parameter is OPTIONAL. This Header Parameter MUST be understood and processed by implementations.

Other values MAY be used. Compression algorithm values can be registered in the IANA JSON Web Encryption Compression Algorithm registry defined in

4.1.4. "jku" (JWK Set URL) Header Parameter

This parameter has the same meaning, syntax, and processing rules as the jku Header Parameter defined in Section 4.1.2 of [JWS], except that the JWK Set resource contains the public key to which the JWE was encrypted; this can be used to determine the private key needed to decrypt the JWE.

4.1.5. "jwk" (JSON Web Key) Header Parameter

This parameter has the same meaning, syntax, and processing rules as the jwk Header Parameter defined in Section 4.1.3 of [JWS], except that the key is the public key to which the JWE was encrypted; this can be used to determine the private key needed to decrypt the JWE.

4.1.6. "kid" (Key ID) Header Parameter

This parameter has the same meaning, syntax, and processing rules as the kid Header Parameter defined in Section 4.1.4 of [JWS], except that the key hint references the public key to which the JWE was encrypted; this can be used to determine the private key needed to decrypt the JWE. This parameter allows originators to explicitly signal a change of key to JWE recipients.

4.1.7. "x5u" (X.509 URL) Header Parameter

This parameter has the same meaning, syntax, and processing rules as the x5u Header Parameter defined in Section 4.1.5 of [JWS], except that the X.509 public key certificate or certificate chain [RFC5280] contains the public key to which the JWE was encrypted; this can be used to determine the private key needed to decrypt the JWE.

4.1.8. "x5c" (X.509 Certificate Chain) Header Parameter

This parameter has the same meaning, syntax, and processing rules as the x5c Header Parameter defined in Section 4.1.6 of [JWS], except that the X.509 public key certificate or certificate chain [RFC5280] contains the public key to which the JWE was encrypted; this can be used to determine the private key needed to decrypt the JWE.

See Appendix B of [JWS] for an example x5c value.

4.1.9. "x5t" (X.509 Certificate SHA-1 Thumbprint) Header Parameter

This parameter has the same meaning, syntax, and processing rules as the x5t Header Parameter defined in Section 4.1.7 of [JWS], except that certificate referenced by the thumbprint contains the public key to which the JWE was encrypted; this can be used to determine the private key needed to decrypt the JWE.

4.1.10. "typ" (Type) Header Parameter

This parameter has the same meaning, syntax, and processing rules as the typ Header Parameter defined in Section 4.1.8 of [JWS], except that the type is of this complete JWE object.

4.1.11. "cty" (Content Type) Header Parameter

This parameter has the same meaning, syntax, and processing rules as the cty Header Parameter defined in Section 4.1.9 of [JWS], except that the type is of the secured content (the plaintext).

4.1.12. "crit" (Critical) Header Parameter

This parameter has the same meaning, syntax, and processing rules as the crit Header Parameter defined in Section 4.1.10 of [JWS], except that JWE Header Parameters are being referred to, rather than JWS Header Parameters.

4.2. Public Header Parameter Names

Additional Header Parameter names can be defined by those using JWEs. However, in order to prevent collisions, any new Header Parameter name should either be registered in the IANA JSON Web Signature and Encryption Header Parameters registry defined in [JWS] or be a Public Name: a value that contains a Collision-Resistant Name. In each case, the definer of the name or value needs to take reasonable precautions to make sure they are in control of the part of the namespace they use to define the Header Parameter name.

New Header Parameters should be introduced sparingly, as they can result in non-interoperable JWEs.

4.3. Private Header Parameter Names

A producer and consumer of a JWE may agree to use Header Parameter names that are Private Names: names that are not Registered Header Parameter names Section 4.1 or Public Header Parameter names Section 4.2. Unlike Public Header Parameter names, Private Header Parameter names are subject to collision and should be used with caution.

5. Producing and Consuming JWEs

5.1. Message Encryption

The message encryption process is as follows. The order of the steps is not significant in cases where there are no dependencies between the inputs and outputs of the steps.

  1. Determine the Key Management Mode employed by the algorithm used to determine the Content Encryption Key (CEK) value. (This is the algorithm recorded in the alg (algorithm) Header Parameter of the resulting JWE.)
  2. When Key Wrapping, Key Encryption, or Key Agreement with Key Wrapping are employed, generate a random Content Encryption Key (CEK) value. See RFC 4086 [RFC4086] for considerations on generating random values. The CEK MUST have a length equal to that required for the content encryption algorithm.
  3. When Direct Key Agreement or Key Agreement with Key Wrapping are employed, use the key agreement algorithm to compute the value of the agreed upon key. When Direct Key Agreement is employed, let the Content Encryption Key (CEK) be the agreed upon key. When Key Agreement with Key Wrapping is employed, the agreed upon key will be used to wrap the CEK.
  4. When Key Wrapping, Key Encryption, or Key Agreement with Key Wrapping are employed, encrypt the CEK to the recipient and let the result be the JWE Encrypted Key.
  5. When Direct Key Agreement or Direct Encryption are employed, let the JWE Encrypted Key be the empty octet sequence.
  6. When Direct Encryption is employed, let the Content Encryption Key (CEK) be the shared symmetric key.
  7. Compute the encoded key value BASE64URL(JWE Encrypted Key).
  8. If the JWE JSON Serialization is being used, repeat this process (steps 1-7) for each recipient.
  9. Generate a random JWE Initialization Vector of the correct size for the content encryption algorithm (if required for the algorithm); otherwise, let the JWE Initialization Vector be the empty octet sequence.
  10. Compute the encoded initialization vector value BASE64URL(JWE Initialization Vector).
  11. If a zip parameter was included, compress the Plaintext using the specified compression algorithm.
  12. Serialize the (compressed) Plaintext into an octet sequence M.
  13. Create the JSON object(s) containing the desired set of Header Parameters, which together comprise the JWE Header: the JWE Protected Header, and if the JWE JSON Serialization is being used, the JWE Shared Unprotected Header and the JWE Per-Recipient Unprotected Header.
  14. Compute the Encoded Protected Header value BASE64URL(UTF8(JWE Protected Header)). If the JWE Protected Header is not present (which can only happen when using the JWE JSON Serialization and no protected member is present), let this value be the empty string.
  15. Let the Additional Authenticated Data encryption parameter be ASCII(Encoded Protected Header). However if a JWE AAD value is present (which can only be the case when using the JWE JSON Serialization), instead let the Additional Authenticated Data encryption parameter be ASCII(Encoded Protected Header || '.' || BASE64URL(JWE AAD)).
  16. Encrypt M using the CEK, the JWE Initialization Vector, and the Additional Authenticated Data value using the specified content encryption algorithm to create the JWE Ciphertext value and the JWE Authentication Tag (which is the Authentication Tag output from the encryption operation).
  17. Compute the encoded ciphertext value BASE64URL(JWE Ciphertext).
  18. Compute the encoded authentication tag value BASE64URL(JWE Authentication Tag).
  19. The five encoded values are used in both the JWE Compact Serialization and the JWE JSON Serialization representations.
  20. If a JWE AAD value is present, compute the encoded AAD value BASE64URL(JWE AAD).
  21. Create the desired serialized output. The Compact Serialization of this result is the string BASE64URL(UTF8(JWE Protected Header)) || '.' || BASE64URL(JWE Encrypted Key) || '.' || BASE64URL(JWE Initialization Vector) || '.' || BASE64URL(JWE Ciphertext) || '.' || BASE64URL(JWE Authentication Tag). The JWE JSON Serialization is described in Section 7.2.

5.2. Message Decryption

The message decryption process is the reverse of the encryption process. The order of the steps is not significant in cases where there are no dependencies between the inputs and outputs of the steps. If any of these steps fails, the encrypted content cannot be validated.

It is an application decision which recipients' encrypted content must successfully validate for the JWE to be accepted. In some cases, encrypted content for all recipients must successfully validate or the JWE will be rejected. In other cases, only the encrypted content for a single recipient needs to be successfully validated. However, in all cases, the encrypted content for at least one recipient MUST successfully validate or the JWE MUST be rejected.

  1. Parse the JWE representation to extract the serialized values for the components of the JWE -- when using the JWE Compact Serialization, the base64url encoded representations of the JWE Protected Header, the JWE Encrypted Key, the JWE Initialization Vector, the JWE Ciphertext, and the JWE Authentication Tag, and when using the JWE JSON Serialization, also the base64url encoded representation of the JWE AAD and the unencoded JWE Shared Unprotected Header and JWE Per-Recipient Unprotected Header values. When using the JWE Compact Serialization, the JWE Protected Header, the JWE Encrypted Key, the JWE Initialization Vector, the JWE Ciphertext, and the JWE Authentication Tag are represented as base64url encoded values in that order, separated by four period ('.') characters. The JWE JSON Serialization is described in Section 7.2.
  2. The encoded representations of the JWE Protected Header, the JWE Encrypted Key, the JWE Initialization Vector, the JWE Ciphertext, the JWE Authentication Tag, and the JWE AAD MUST be successfully base64url decoded following the restriction that no padding characters have been used.
  3. The octet sequence resulting from decoding the encoded JWE Protected Header MUST be a UTF-8 encoded representation of a completely valid JSON object conforming to [RFC7158], which is the JWE Protected Header.
  4. If using the JWE Compact Serialization, let the JWE Header be the JWE Protected Header; otherwise, when using the JWE JSON Serialization, let the JWE Header be the union of the members of the JWE Protected Header, the JWE Shared Unprotected Header and the corresponding JWE Per-Recipient Unprotected Header, all of which must be completely valid JSON objects.
  5. The resulting JWE Header MUST NOT contain duplicate Header Parameter names. When using the JWE JSON Serialization, this restriction includes that the same Header Parameter name also MUST NOT occur in distinct JSON object values that together comprise the JWE Header.
  6. Verify that the implementation understands and can process all fields that it is required to support, whether required by this specification, by the algorithms being used, or by the crit Header Parameter value, and that the values of those parameters are also understood and supported.
  7. Determine the Key Management Mode employed by the algorithm specified by the alg (algorithm) Header Parameter.
  8. Verify that the JWE uses a key known to the recipient.
  9. When Direct Key Agreement or Key Agreement with Key Wrapping are employed, use the key agreement algorithm to compute the value of the agreed upon key. When Direct Key Agreement is employed, let the Content Encryption Key (CEK) be the agreed upon key. When Key Agreement with Key Wrapping is employed, the agreed upon key will be used to decrypt the JWE Encrypted Key.
  10. When Key Wrapping, Key Encryption, or Key Agreement with Key Wrapping are employed, decrypt the JWE Encrypted Key to produce the Content Encryption Key (CEK). The CEK MUST have a length equal to that required for the content encryption algorithm. Note that when there are multiple recipients, each recipient will only be able decrypt any JWE Encrypted Key values that were encrypted to a key in that recipient's possession. It is therefore normal to only be able to decrypt one of the per-recipient JWE Encrypted Key values to obtain the CEK value. To mitigate the attacks described in RFC 3218 [RFC3218], the recipient MUST NOT distinguish between format, padding, and length errors of encrypted keys. It is strongly recommended, in the event of receiving an improperly formatted key, that the receiver substitute a randomly generated CEK and proceed to the next step, to mitigate timing attacks.
  11. When Direct Key Agreement or Direct Encryption are employed, verify that the JWE Encrypted Key value is empty octet sequence.
  12. When Direct Encryption is employed, let the Content Encryption Key (CEK) be the shared symmetric key.
  13. If the JWE JSON Serialization is being used, repeat this process (steps 4-12) for each recipient contained in the representation until the CEK value has been determined.
  14. Compute the Encoded Protected Header value BASE64URL(UTF8(JWE Protected Header)). If the JWE Protected Header is not present (which can only happen when using the JWE JSON Serialization and no protected member is present), let this value be the empty string.
  15. Let the Additional Authenticated Data encryption parameter be ASCII(Encoded Protected Header). However if a JWE AAD value is present (which can only be the case when using the JWE JSON Serialization), instead let the Additional Authenticated Data encryption parameter be ASCII(Encoded Protected Header || '.' || BASE64URL(JWE AAD)).
  16. Decrypt the JWE Ciphertext using the CEK, the JWE Initialization Vector, the Additional Authenticated Data value, and the JWE Authentication Tag (which is the Authentication Tag input to the calculation) using the specified content encryption algorithm, returning the decrypted plaintext and validating the JWE Authentication Tag in the manner specified for the algorithm, rejecting the input without emitting any decrypted output if the JWE Authentication Tag is incorrect.
  17. If a zip parameter was included, uncompress the decrypted plaintext using the specified compression algorithm.
  18. If all the previous steps succeeded, output the resulting Plaintext.

5.3. String Comparison Rules

The string comparison rules for this specification are the same as those defined in Section 5.3 of [JWS].

6. Key Identification

The key identification methods for this specification are the same as those defined in Section 6 of [JWS], except that the key being identified is the public key to which the JWE was encrypted.

7. Serializations

JWE objects use one of two serializations, the JWE Compact Serialization or the JWE JSON Serialization. Applications using this specification need to specify what serialization and serialization features are used for that application. For instance, applications might specify that only the JWE JSON Serialization is used, that only JWE JSON Serialization support for a single recipient is used, or that support for multiple recipients is used. JWE implementations only need to implement the features needed for the applications they are designed to support.

7.1. JWE Compact Serialization

The JWE Compact Serialization represents encrypted content as a compact URL-safe string. This string is BASE64URL(UTF8(JWE Protected Header)) || '.' || BASE64URL(JWE Encrypted Key) || '.' || BASE64URL(JWE Initialization Vector) || '.' || BASE64URL(JWE Ciphertext) || '.' || BASE64URL(JWE Authentication Tag). Only one recipient is supported by the JWE Compact Serialization and it provides no syntax to represent JWE Shared Unprotected Header, JWE Per-Recipient Unprotected Header, or JWE AAD values.

7.2. JWE JSON Serialization

The JWE JSON Serialization represents encrypted content as a JSON object. Content using the JWE JSON Serialization can be encrypted to more than one recipient. This representation is neither optimized for compactness nor URL-safe.

The following members are defined for use in top-level JSON objects used for the JWE JSON Serialization:

protected

The protected member MUST be present and contain the value BASE64URL(UTF8(JWE Protected Header)) when the JWE Protected Header value is non-empty; otherwise, it MUST be absent. These Header Parameter values are integrity protected.
unprotected

The unprotected member MUST be present and contain the value JWE Shared Unprotected Header when the JWE Shared Unprotected Header value is non-empty; otherwise, it MUST be absent. This value is represented as an unencoded JSON object, rather than as a string. These Header Parameter values are not integrity protected.
iv

The iv member MUST be present and contain the value BASE64URL(JWE Initialization Vector) when the JWE Initialization Vector value is non-empty; otherwise, it MUST be absent.
aad

The aad member MUST be present and contain the value BASE64URL(JWE AAD)) when the JWE AAD value is non-empty; otherwise, it MUST be absent. A JWE AAD value can be included to supply a base64url encoded value to be integrity protected but not encrypted.
ciphertext

The ciphertext member MUST be present and contain the value BASE64URL(JWE Ciphertext).
tag

The tag member MUST be present and contain the value BASE64URL(JWE Authentication Tag) when the JWE Authentication Tag value is non-empty; otherwise, it MUST be absent.
recipients

The recipients member value MUST be an array of JSON objects. Each object contains information specific to a single recipient. This member MUST be present, even if the array elements contain only the empty JSON object {} (which can happen when all Header Parameter values are shared between all recipients and when no encrypted key is used, such as when doing Direct Encryption).

The following members are defined for use in the JSON objects that are elements of the recipients array:

header

The header member MUST be present and contain the value JWE Per-Recipient Unprotected Header when the JWE Per-Recipient Unprotected Header value is non-empty; otherwise, it MUST be absent. This value is represented as an unencoded JSON object, rather than as a string. These Header Parameter values are not integrity protected.
encrypted_key

The encrypted_key member MUST be present and contain the value BASE64URL(JWE Encrypted Key) when the JWE Encrypted Key value is non-empty; otherwise, it MUST be absent.

At least one of the header, protected, and unprotected members MUST be present so that alg and enc Header Parameter values are conveyed for each recipient computation.

Additional members can be present in both the JSON objects defined above; if not understood by implementations encountering them, they MUST be ignored.

Some Header Parameters, including the alg parameter, can be shared among all recipient computations. Header Parameters in the JWE Protected Header and JWE Shared Unprotected Header values are shared among all recipients.

The Header Parameter values used when creating or validating per-recipient Ciphertext and Authentication Tag values are the union of the three sets of Header Parameter values that may be present: (1) the JWE Protected Header represented in the protected member, (2) the JWE Shared Unprotected Header represented in the unprotected member, and (3) the JWE Per-Recipient Unprotected Header represented in the header member of the recipient's array element. The union of these sets of Header Parameters comprises the JWE Header. The Header Parameter names in the three locations MUST be disjoint.

Each JWE Encrypted Key value is computed using the parameters of the corresponding JWE Header value in the same manner as for the JWE Compact Serialization. This has the desirable property that each JWE Encrypted Key value in the recipients array is identical to the value that would have been computed for the same parameter in the JWE Compact Serialization. Likewise, the JWE Ciphertext and JWE Authentication Tag values match those produced for the JWE Compact Serialization, provided that the JWE Protected Header value (which represents the integrity-protected Header Parameter values) matches that used in the JWE Compact Serialization.

All recipients use the same JWE Protected Header, JWE Initialization Vector, JWE Ciphertext, and JWE Authentication Tag values, when present, resulting in potentially significant space savings if the message is large. Therefore, all Header Parameters that specify the treatment of the Plaintext value MUST be the same for all recipients. This primarily means that the enc (encryption algorithm) Header Parameter value in the JWE Header for each recipient and any parameters of that algorithm MUST be the same.

In summary, the syntax of a JWE using the JWE JSON Serialization is as follows:

  {"protected":"<integrity-protected shared header contents>",
   "unprotected":<non-integrity-protected shared header contents>,
   "recipients":[
    {"header":<per-recipient unprotected header 1 contents>,
     "encrypted_key":"<encrypted key 1 contents>"},
    ...
    {"header":<per-recipient unprotected header N contents>,
     "encrypted_key":"<encrypted key N contents>"}],
   "aad":"<additional authenticated data contents>",
   "iv":"<initialization vector contents>",
   "ciphertext":"<ciphertext contents>",
   "tag":"<authentication tag contents>"
  }

See Appendix A.4 for an example of computing a JWE using the JWE JSON Serialization.

8. TLS Requirements

The TLS requirements for this specification are the same as those defined in Section 8 of [JWS].

9. Distinguishing between JWS and JWE Objects

There are several ways of distinguishing whether an object is a JWS or JWE object. All these methods will yield the same result for all legal input values; they may yield different results for malformed inputs.

10. IANA Considerations

10.1. JSON Web Signature and Encryption Header Parameters Registration

This specification registers the Header Parameter names defined in Section 4.1 in the IANA JSON Web Signature and Encryption Header Parameters registry defined in [JWS].

10.1.1. Registry Contents

11. Security Considerations

All of the security issues faced by any cryptographic application must be faced by a JWS/JWE/JWK agent. Among these issues are protecting the user's private and symmetric keys, preventing various attacks, and helping the user avoid mistakes such as inadvertently encrypting a message for the wrong recipient. The entire list of security considerations is beyond the scope of this document.

All the security considerations in the JWS specification also apply to this specification. Likewise, all the security considerations in XML Encryption 1.1 [W3C.CR-xmlenc-core1-20120313] also apply, other than those that are XML specific.

When decrypting, particular care must be taken not to allow the JWE recipient to be used as an oracle for decrypting messages. RFC 3218 [RFC3218] should be consulted for specific countermeasures to attacks on RSAES-PKCS1-V1_5. An attacker might modify the contents of the alg parameter from RSA-OAEP to RSA1_5 in order to generate a formatting error that can be detected and used to recover the CEK even if RSAES OAEP was used to encrypt the CEK. It is therefore particularly important to report all formatting errors to the CEK, Additional Authenticated Data, or ciphertext as a single error when the encrypted content is rejected.

Additionally, this type of attack can be prevented by the use of "key tainting". This method restricts the use of a key to a limited set of algorithms -- usually one. This means, for instance, that if the key is marked as being for RSA-OAEP only, any attempt to decrypt a message using the RSA1_5 algorithm with that key would fail immediately due to invalid use of the key.

12. References

12.1. Normative References

[ECMAScript] Ecma International, "ECMAScript Language Specification, 5.1 Edition", ECMA 262, June 2011.
[JWA] Jones, M., "JSON Web Algorithms (JWA)", Internet-Draft draft-ietf-jose-json-web-algorithms, March 2014.
[JWK] Jones, M., "JSON Web Key (JWK)", Internet-Draft draft-ietf-jose-json-web-key, March 2014.
[JWS] Jones, M., Bradley, J. and N. Sakimura, "JSON Web Signature (JWS)", Internet-Draft draft-ietf-jose-json-web-signature, March 2014.
[RFC1951] Deutsch, P., "DEFLATE Compressed Data Format Specification version 1.3", RFC 1951, May 1996.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC3629] Yergeau, F., "UTF-8, a transformation format of ISO 10646", STD 63, RFC 3629, November 2003.
[RFC5280] Cooper, D., Santesson, S., Farrell, S., Boeyen, S., Housley, R. and W. Polk, "Internet X.509 Public Key Infrastructure Certificate and Certificate Revocation List (CRL) Profile", RFC 5280, May 2008.
[RFC7158] Bray, T., "The JavaScript Object Notation (JSON) Data Interchange Format", RFC 7158, March 2014.
[USASCII] American National Standards Institute, "Coded Character Set -- 7-bit American Standard Code for Information Interchange", ANSI X3.4, 1986.

12.2. Informative References

[I-D.mcgrew-aead-aes-cbc-hmac-sha2] McGrew, D. and K. Paterson, "Authenticated Encryption with AES-CBC and HMAC-SHA", Internet-Draft draft-mcgrew-aead-aes-cbc-hmac-sha2-01, October 2012.
[I-D.rescorla-jsms] Rescorla, E. and J. Hildebrand, "JavaScript Message Security Format", Internet-Draft draft-rescorla-jsms-00, March 2011.
[JSE] Bradley, J. and N. Sakimura (editor), "JSON Simple Encryption", September 2010.
[RFC3218] Rescorla, E., "Preventing the Million Message Attack on Cryptographic Message Syntax", RFC 3218, January 2002.
[RFC4086] Eastlake, D., Schiller, J. and S. Crocker, "Randomness Requirements for Security", BCP 106, RFC 4086, June 2005.
[RFC5652] Housley, R., "Cryptographic Message Syntax (CMS)", STD 70, RFC 5652, September 2009.
[W3C.CR-xmlenc-core1-20120313] Eastlake, D., Reagle, J., Roessler, T. and F. Hirsch, "XML Encryption Syntax and Processing Version 1.1", World Wide Web Consortium CR CR-xmlenc-core1-20120313, March 2012.

Appendix A. JWE Examples

This section provides examples of JWE computations.

A.1. Example JWE using RSAES OAEP and AES GCM

This example encrypts the plaintext "The true sign of intelligence is not knowledge but imagination." to the recipient using RSAES OAEP for key encryption and AES GCM for content encryption. The representation of this plaintext is:

[84, 104, 101, 32, 116, 114, 117, 101, 32, 115, 105, 103, 110, 32, 111, 102, 32, 105, 110, 116, 101, 108, 108, 105, 103, 101, 110, 99, 101, 32, 105, 115, 32, 110, 111, 116, 32, 107, 110, 111, 119, 108, 101, 100, 103, 101, 32, 98, 117, 116, 32, 105, 109, 97, 103, 105, 110, 97, 116, 105, 111, 110, 46]

A.1.1. JWE Header

The following example JWE Protected Header declares that:

  {"alg":"RSA-OAEP","enc":"A256GCM"}

Encoding this JWE Protected Header as BASE64URL(UTF8(JWE Protected Header)) gives this value:

  eyJhbGciOiJSU0EtT0FFUCIsImVuYyI6IkEyNTZHQ00ifQ

A.1.2. Content Encryption Key (CEK)

Generate a 256 bit random Content Encryption Key (CEK). In this example, the value is:

[177, 161, 244, 128, 84, 143, 225, 115, 63, 180, 3, 255, 107, 154, 212, 246, 138, 7, 110, 91, 112, 46, 34, 105, 47, 130, 203, 46, 122, 234, 64, 252]

A.1.3. Key Encryption

Encrypt the CEK with the recipient's public key using the RSAES OAEP algorithm to produce the JWE Encrypted Key. This example uses the RSA key represented in JSON Web Key [JWK] format below (with line breaks for display purposes only):

  {"kty":"RSA",
   "n":"oahUIoWw0K0usKNuOR6H4wkf4oBUXHTxRvgb48E-BVvxkeDNjbC4he8rUW
        cJoZmds2h7M70imEVhRU5djINXtqllXI4DFqcI1DgjT9LewND8MW2Krf3S
        psk_ZkoFnilakGygTwpZ3uesH-PFABNIUYpOiN15dsQRkgr0vEhxN92i2a
        sbOenSZeyaxziK72UwxrrKoExv6kc5twXTq4h-QChLOln0_mtUZwfsRaMS
        tPs6mS6XrgxnxbWhojf663tuEQueGC-FCMfra36C9knDFGzKsNa7LZK2dj
        YgyD3JR_MB_4NUJW_TqOQtwHYbxevoJArm-L5StowjzGy-_bq6Gw",
   "e":"AQAB",
   "d":"kLdtIj6GbDks_ApCSTYQtelcNttlKiOyPzMrXHeI-yk1F7-kpDxY4-WY5N
        WV5KntaEeXS1j82E375xxhWMHXyvjYecPT9fpwR_M9gV8n9Hrh2anTpTD9
        3Dt62ypW3yDsJzBnTnrYu1iwWRgBKrEYY46qAZIrA2xAwnm2X7uGR1hghk
        qDp0Vqj3kbSCz1XyfCs6_LehBwtxHIyh8Ripy40p24moOAbgxVw3rxT_vl
        t3UVe4WO3JkJOzlpUf-KTVI2Ptgm-dARxTEtE-id-4OJr0h-K-VFs3VSnd
        VTIznSxfyrj8ILL6MG_Uv8YAu7VILSB3lOW085-4qE3DzgrTjgyQ"
  }

The resulting JWE Encrypted Key value is:

[56, 163, 154, 192, 58, 53, 222, 4, 105, 218, 136, 218, 29, 94, 203, 22, 150, 92, 129, 94, 211, 232, 53, 89, 41, 60, 138, 56, 196, 216, 82, 98, 168, 76, 37, 73, 70, 7, 36, 8, 191, 100, 136, 196, 244, 220, 145, 158, 138, 155, 4, 117, 141, 230, 199, 247, 173, 45, 182, 214, 74, 177, 107, 211, 153, 11, 205, 196, 171, 226, 162, 128, 171, 182, 13, 237, 239, 99, 193, 4, 91, 219, 121, 223, 107, 167, 61, 119, 228, 173, 156, 137, 134, 200, 80, 219, 74, 253, 56, 185, 91, 177, 34, 158, 89, 154, 205, 96, 55, 18, 138, 43, 96, 218, 215, 128, 124, 75, 138, 243, 85, 25, 109, 117, 140, 26, 155, 249, 67, 167, 149, 231, 100, 6, 41, 65, 214, 251, 232, 87, 72, 40, 182, 149, 154, 168, 31, 193, 126, 215, 89, 28, 111, 219, 125, 182, 139, 235, 195, 197, 23, 234, 55, 58, 63, 180, 68, 202, 206, 149, 75, 205, 248, 176, 67, 39, 178, 60, 98, 193, 32, 238, 122, 96, 158, 222, 57, 183, 111, 210, 55, 188, 215, 206, 180, 166, 150, 166, 106, 250, 55, 229, 72, 40, 69, 214, 216, 104, 23, 40, 135, 212, 28, 127, 41, 80, 175, 174, 168, 115, 171, 197, 89, 116, 92, 103, 246, 83, 216, 182, 176, 84, 37, 147, 35, 45, 219, 172, 99, 226, 233, 73, 37, 124, 42, 72, 49, 242, 35, 127, 184, 134, 117, 114, 135, 206]

Encoding this JWE Encrypted Key as BASE64URL(JWE Encrypted Key) gives this value (with line breaks for display purposes only):

  OKOawDo13gRp2ojaHV7LFpZcgV7T6DVZKTyKOMTYUmKoTCVJRgckCL9kiMT03JGe
  ipsEdY3mx_etLbbWSrFr05kLzcSr4qKAq7YN7e9jwQRb23nfa6c9d-StnImGyFDb
  Sv04uVuxIp5Zms1gNxKKK2Da14B8S4rzVRltdYwam_lDp5XnZAYpQdb76FdIKLaV
  mqgfwX7XWRxv2322i-vDxRfqNzo_tETKzpVLzfiwQyeyPGLBIO56YJ7eObdv0je8
  1860ppamavo35UgoRdbYaBcoh9QcfylQr66oc6vFWXRcZ_ZT2LawVCWTIy3brGPi
  6UklfCpIMfIjf7iGdXKHzg

A.1.4. Initialization Vector

Generate a random 96 bit JWE Initialization Vector. In this example, the value is:

[227, 197, 117, 252, 2, 219, 233, 68, 180, 225, 77, 219]

Encoding this JWE Initialization Vector as BASE64URL(JWE Initialization Vector) gives this value:

  48V1_ALb6US04U3b

A.1.5. Additional Authenticated Data

Let the Additional Authenticated Data encryption parameter be ASCII(BASE64URL(UTF8(JWE Protected Header))). This value is:

[101, 121, 74, 104, 98, 71, 99, 105, 79, 105, 74, 83, 85, 48, 69, 116, 84, 48, 70, 70, 85, 67, 73, 115, 73, 109, 86, 117, 89, 121, 73, 54, 73, 107, 69, 121, 78, 84, 90, 72, 81, 48, 48, 105, 102, 81]

A.1.6. Content Encryption

Encrypt the Plaintext with AES GCM using the CEK as the encryption key, the JWE Initialization Vector, and the Additional Authenticated Data value above, requesting a 128 bit Authentication Tag output. The resulting Ciphertext is:

[229, 236, 166, 241, 53, 191, 115, 196, 174, 43, 73, 109, 39, 122, 233, 96, 140, 206, 120, 52, 51, 237, 48, 11, 190, 219, 186, 80, 111, 104, 50, 142, 47, 167, 59, 61, 181, 127, 196, 21, 40, 82, 242, 32, 123, 143, 168, 226, 73, 216, 176, 144, 138, 247, 106, 60, 16, 205, 160, 109, 64, 63, 192]

The resulting Authentication Tag value is:

[92, 80, 104, 49, 133, 25, 161, 215, 173, 101, 219, 211, 136, 91, 210, 145]

Encoding this JWE Ciphertext as BASE64URL(JWE Ciphertext) gives this value (with line breaks for display purposes only):

  5eym8TW_c8SuK0ltJ3rpYIzOeDQz7TALvtu6UG9oMo4vpzs9tX_EFShS8iB7j6ji
  SdiwkIr3ajwQzaBtQD_A

Encoding this JWE Authentication Tag as BASE64URL(JWE Authentication Tag) gives this value:

  XFBoMYUZodetZdvTiFvSkQ

A.1.7. Complete Representation

Assemble the final representation: The Compact Serialization of this result is the string BASE64URL(UTF8(JWE Protected Header)) || '.' || BASE64URL(JWE Encrypted Key) || '.' || BASE64URL(JWE Initialization Vector) || '.' || BASE64URL(JWE Ciphertext) || '.' || BASE64URL(JWE Authentication Tag).

The final result in this example (with line breaks for display purposes only) is:

  eyJhbGciOiJSU0EtT0FFUCIsImVuYyI6IkEyNTZHQ00ifQ.
  OKOawDo13gRp2ojaHV7LFpZcgV7T6DVZKTyKOMTYUmKoTCVJRgckCL9kiMT03JGe
  ipsEdY3mx_etLbbWSrFr05kLzcSr4qKAq7YN7e9jwQRb23nfa6c9d-StnImGyFDb
  Sv04uVuxIp5Zms1gNxKKK2Da14B8S4rzVRltdYwam_lDp5XnZAYpQdb76FdIKLaV
  mqgfwX7XWRxv2322i-vDxRfqNzo_tETKzpVLzfiwQyeyPGLBIO56YJ7eObdv0je8
  1860ppamavo35UgoRdbYaBcoh9QcfylQr66oc6vFWXRcZ_ZT2LawVCWTIy3brGPi
  6UklfCpIMfIjf7iGdXKHzg.
  48V1_ALb6US04U3b.
  5eym8TW_c8SuK0ltJ3rpYIzOeDQz7TALvtu6UG9oMo4vpzs9tX_EFShS8iB7j6ji
  SdiwkIr3ajwQzaBtQD_A.
  XFBoMYUZodetZdvTiFvSkQ

A.1.8. Validation

This example illustrates the process of creating a JWE with RSAES OAEP for key encryption and AES GCM for content encryption. These results can be used to validate JWE decryption implementations for these algorithms. Note that since the RSAES OAEP computation includes random values, the encryption results above will not be completely reproducible. However, since the AES GCM computation is deterministic, the JWE Encrypted Ciphertext values will be the same for all encryptions performed using these inputs.

A.2. Example JWE using RSAES-PKCS1-V1_5 and AES_128_CBC_HMAC_SHA_256

This example encrypts the plaintext "Live long and prosper." to the recipient using RSAES-PKCS1-V1_5 for key encryption and AES_128_CBC_HMAC_SHA_256 for content encryption. The representation of this plaintext is:

[76, 105, 118, 101, 32, 108, 111, 110, 103, 32, 97, 110, 100, 32, 112, 114, 111, 115, 112, 101, 114, 46]

A.2.1. JWE Header

The following example JWE Protected Header declares that:

  {"alg":"RSA1_5","enc":"A128CBC-HS256"}

Encoding this JWE Protected Header as BASE64URL(UTF8(JWE Protected Header)) gives this value:

  eyJhbGciOiJSU0ExXzUiLCJlbmMiOiJBMTI4Q0JDLUhTMjU2In0

A.2.2. Content Encryption Key (CEK)

Generate a 256 bit random Content Encryption Key (CEK). In this example, the key value is:

[4, 211, 31, 197, 84, 157, 252, 254, 11, 100, 157, 250, 63, 170, 106, 206, 107, 124, 212, 45, 111, 107, 9, 219, 200, 177, 0, 240, 143, 156, 44, 207]

A.2.3. Key Encryption

Encrypt the CEK with the recipient's public key using the RSAES-PKCS1-V1_5 algorithm to produce the JWE Encrypted Key. This example uses the RSA key represented in JSON Web Key [JWK] format below (with line breaks for display purposes only):

  {"kty":"RSA",
   "n":"sXchDaQebHnPiGvyDOAT4saGEUetSyo9MKLOoWFsueri23bOdgWp4Dy1Wl
        UzewbgBHod5pcM9H95GQRV3JDXboIRROSBigeC5yjU1hGzHHyXss8UDpre
        cbAYxknTcQkhslANGRUZmdTOQ5qTRsLAt6BTYuyvVRdhS8exSZEy_c4gs_
        7svlJJQ4H9_NxsiIoLwAEk7-Q3UXERGYw_75IDrGA84-lA_-Ct4eTlXHBI
        Y2EaV7t7LjJaynVJCpkv4LKjTTAumiGUIuQhrNhZLuF_RJLqHpM2kgWFLU
        7-VTdL1VbC2tejvcI2BlMkEpk1BzBZI0KQB0GaDWFLN-aEAw3vRw",
   "e":"AQAB",
   "d":"VFCWOqXr8nvZNyaaJLXdnNPXZKRaWCjkU5Q2egQQpTBMwhprMzWzpR8Sxq
        1OPThh_J6MUD8Z35wky9b8eEO0pwNS8xlh1lOFRRBoNqDIKVOku0aZb-ry
        nq8cxjDTLZQ6Fz7jSjR1Klop-YKaUHc9GsEofQqYruPhzSA-QgajZGPbE_
        0ZaVDJHfyd7UUBUKunFMScbflYAAOYJqVIVwaYR5zWEEceUjNnTNo_CVSj
        -VvXLO5VZfCUAVLgW4dpf1SrtZjSt34YLsRarSb127reG_DUwg9Ch-Kyvj
        T1SkHgUWRVGcyly7uvVGRSDwsXypdrNinPA4jlhoNdizK2zF2CWQ"
  }

The resulting JWE Encrypted Key value is:

[80, 104, 72, 58, 11, 130, 236, 139, 132, 189, 255, 205, 61, 86, 151, 176, 99, 40, 44, 233, 176, 189, 205, 70, 202, 169, 72, 40, 226, 181, 156, 223, 120, 156, 115, 232, 150, 209, 145, 133, 104, 112, 237, 156, 116, 250, 65, 102, 212, 210, 103, 240, 177, 61, 93, 40, 71, 231, 223, 226, 240, 157, 15, 31, 150, 89, 200, 215, 198, 203, 108, 70, 117, 66, 212, 238, 193, 205, 23, 161, 169, 218, 243, 203, 128, 214, 127, 253, 215, 139, 43, 17, 135, 103, 179, 220, 28, 2, 212, 206, 131, 158, 128, 66, 62, 240, 78, 186, 141, 125, 132, 227, 60, 137, 43, 31, 152, 199, 54, 72, 34, 212, 115, 11, 152, 101, 70, 42, 219, 233, 142, 66, 151, 250, 126, 146, 141, 216, 190, 73, 50, 177, 146, 5, 52, 247, 28, 197, 21, 59, 170, 247, 181, 89, 131, 241, 169, 182, 246, 99, 15, 36, 102, 166, 182, 172, 197, 136, 230, 120, 60, 58, 219, 243, 149, 94, 222, 150, 154, 194, 110, 227, 225, 112, 39, 89, 233, 112, 207, 211, 241, 124, 174, 69, 221, 179, 107, 196, 225, 127, 167, 112, 226, 12, 242, 16, 24, 28, 120, 182, 244, 213, 244, 153, 194, 162, 69, 160, 244, 248, 63, 165, 141, 4, 207, 249, 193, 79, 131, 0, 169, 233, 127, 167, 101, 151, 125, 56, 112, 111, 248, 29, 232, 90, 29, 147, 110, 169, 146, 114, 165, 204, 71, 136, 41, 252]

Encoding this JWE Encrypted Key as BASE64URL(JWE Encrypted Key) gives this value (with line breaks for display purposes only):

  UGhIOguC7IuEvf_NPVaXsGMoLOmwvc1GyqlIKOK1nN94nHPoltGRhWhw7Zx0-kFm
  1NJn8LE9XShH59_i8J0PH5ZZyNfGy2xGdULU7sHNF6Gp2vPLgNZ__deLKxGHZ7Pc
  HALUzoOegEI-8E66jX2E4zyJKx-YxzZIItRzC5hlRirb6Y5Cl_p-ko3YvkkysZIF
  NPccxRU7qve1WYPxqbb2Yw8kZqa2rMWI5ng8OtvzlV7elprCbuPhcCdZ6XDP0_F8
  rkXds2vE4X-ncOIM8hAYHHi29NX0mcKiRaD0-D-ljQTP-cFPgwCp6X-nZZd9OHBv
  -B3oWh2TbqmScqXMR4gp_A

A.2.4. Initialization Vector

Generate a random 128 bit JWE Initialization Vector. In this example, the value is:

[3, 22, 60, 12, 43, 67, 104, 105, 108, 108, 105, 99, 111, 116, 104, 101]

Encoding this JWE Initialization Vector as BASE64URL(JWE Initialization Vector) gives this value:

  AxY8DCtDaGlsbGljb3RoZQ

A.2.5. Additional Authenticated Data

Let the Additional Authenticated Data encryption parameter be ASCII(BASE64URL(UTF8(JWE Protected Header))). This value is:

[101, 121, 74, 104, 98, 71, 99, 105, 79, 105, 74, 83, 85, 48, 69, 120, 88, 122, 85, 105, 76, 67, 74, 108, 98, 109, 77, 105, 79, 105, 74, 66, 77, 84, 73, 52, 81, 48, 74, 68, 76, 85, 104, 84, 77, 106, 85, 50, 73, 110, 48]

A.2.6. Content Encryption

Encrypt the Plaintext with AES_128_CBC_HMAC_SHA_256 using the CEK as the encryption key, the JWE Initialization Vector, and the Additional Authenticated Data value above. The steps for doing this using the values from Appendix A.3 are detailed in Appendix B. The resulting Ciphertext is:

[40, 57, 83, 181, 119, 33, 133, 148, 198, 185, 243, 24, 152, 230, 6, 75, 129, 223, 127, 19, 210, 82, 183, 230, 168, 33, 215, 104, 143, 112, 56, 102]

The resulting Authentication Tag value is:

[246, 17, 244, 190, 4, 95, 98, 3, 231, 0, 115, 157, 242, 203, 100, 191]

Encoding this JWE Ciphertext as BASE64URL(JWE Ciphertext) gives this value:

  KDlTtXchhZTGufMYmOYGS4HffxPSUrfmqCHXaI9wOGY

Encoding this JWE Authentication Tag as BASE64URL(JWE Authentication Tag) gives this value:

  9hH0vgRfYgPnAHOd8stkvw

A.2.7. Complete Representation

Assemble the final representation: The Compact Serialization of this result is the string BASE64URL(UTF8(JWE Protected Header)) || '.' || BASE64URL(JWE Encrypted Key) || '.' || BASE64URL(JWE Initialization Vector) || '.' || BASE64URL(JWE Ciphertext) || '.' || BASE64URL(JWE Authentication Tag).

The final result in this example (with line breaks for display purposes only) is:

  eyJhbGciOiJSU0ExXzUiLCJlbmMiOiJBMTI4Q0JDLUhTMjU2In0.
  UGhIOguC7IuEvf_NPVaXsGMoLOmwvc1GyqlIKOK1nN94nHPoltGRhWhw7Zx0-kFm
  1NJn8LE9XShH59_i8J0PH5ZZyNfGy2xGdULU7sHNF6Gp2vPLgNZ__deLKxGHZ7Pc
  HALUzoOegEI-8E66jX2E4zyJKx-YxzZIItRzC5hlRirb6Y5Cl_p-ko3YvkkysZIF
  NPccxRU7qve1WYPxqbb2Yw8kZqa2rMWI5ng8OtvzlV7elprCbuPhcCdZ6XDP0_F8
  rkXds2vE4X-ncOIM8hAYHHi29NX0mcKiRaD0-D-ljQTP-cFPgwCp6X-nZZd9OHBv
  -B3oWh2TbqmScqXMR4gp_A.
  AxY8DCtDaGlsbGljb3RoZQ.
  KDlTtXchhZTGufMYmOYGS4HffxPSUrfmqCHXaI9wOGY.
  9hH0vgRfYgPnAHOd8stkvw

A.2.8. Validation

This example illustrates the process of creating a JWE with RSAES-PKCS1-V1_5 for key encryption and AES_CBC_HMAC_SHA2 for content encryption. These results can be used to validate JWE decryption implementations for these algorithms. Note that since the RSAES-PKCS1-V1_5 computation includes random values, the encryption results above will not be completely reproducible. However, since the AES CBC computation is deterministic, the JWE Encrypted Ciphertext values will be the same for all encryptions performed using these inputs.

A.3. Example JWE using AES Key Wrap and AES_128_CBC_HMAC_SHA_256

This example encrypts the plaintext "Live long and prosper." to the recipient using AES Key Wrap for key encryption and AES GCM for content encryption. The representation of this plaintext is:

[76, 105, 118, 101, 32, 108, 111, 110, 103, 32, 97, 110, 100, 32, 112, 114, 111, 115, 112, 101, 114, 46]

A.3.1. JWE Header

The following example JWE Protected Header declares that:

  {"alg":"A128KW","enc":"A128CBC-HS256"}

Encoding this JWE Protected Header as BASE64URL(UTF8(JWE Protected Header)) gives this value:

  eyJhbGciOiJBMTI4S1ciLCJlbmMiOiJBMTI4Q0JDLUhTMjU2In0

A.3.2. Content Encryption Key (CEK)

Generate a 256 bit random Content Encryption Key (CEK). In this example, the value is:

[4, 211, 31, 197, 84, 157, 252, 254, 11, 100, 157, 250, 63, 170, 106, 206, 107, 124, 212, 45, 111, 107, 9, 219, 200, 177, 0, 240, 143, 156, 44, 207]

A.3.3. Key Encryption

Encrypt the CEK with the shared symmetric key using the AES Key Wrap algorithm to produce the JWE Encrypted Key. This example uses the symmetric key represented in JSON Web Key [JWK] format below:

  {"kty":"oct",
   "k":"GawgguFyGrWKav7AX4VKUg"
  }

The resulting JWE Encrypted Key value is:

[232, 160, 123, 211, 183, 76, 245, 132, 200, 128, 123, 75, 190, 216, 22, 67, 201, 138, 193, 186, 9, 91, 122, 31, 246, 90, 28, 139, 57, 3, 76, 124, 193, 11, 98, 37, 173, 61, 104, 57]

Encoding this JWE Encrypted Key as BASE64URL(JWE Encrypted Key) gives this value:

  6KB707dM9YTIgHtLvtgWQ8mKwboJW3of9locizkDTHzBC2IlrT1oOQ

A.3.4. Initialization Vector

Generate a random 128 bit JWE Initialization Vector. In this example, the value is:

[3, 22, 60, 12, 43, 67, 104, 105, 108, 108, 105, 99, 111, 116, 104, 101]

Encoding this JWE Initialization Vector as BASE64URL(JWE Initialization Vector) gives this value:

  AxY8DCtDaGlsbGljb3RoZQ

A.3.5. Additional Authenticated Data

Let the Additional Authenticated Data encryption parameter be ASCII(BASE64URL(UTF8(JWE Protected Header))). This value is:

[101, 121, 74, 104, 98, 71, 99, 105, 79, 105, 74, 66, 77, 84, 73, 52, 83, 49, 99, 105, 76, 67, 74, 108, 98, 109, 77, 105, 79, 105, 74, 66, 77, 84, 73, 52, 81, 48, 74, 68, 76, 85, 104, 84, 77, 106, 85, 50, 73, 110, 48]

A.3.6. Content Encryption

Encrypt the Plaintext with AES_128_CBC_HMAC_SHA_256 using the CEK as the encryption key, the JWE Initialization Vector, and the Additional Authenticated Data value above. The steps for doing this using the values from this example are detailed in Appendix B. The resulting Ciphertext is:

[40, 57, 83, 181, 119, 33, 133, 148, 198, 185, 243, 24, 152, 230, 6, 75, 129, 223, 127, 19, 210, 82, 183, 230, 168, 33, 215, 104, 143, 112, 56, 102]

The resulting Authentication Tag value is:

[83, 73, 191, 98, 104, 205, 211, 128, 201, 189, 199, 133, 32, 38, 194, 85]

Encoding this JWE Ciphertext as BASE64URL(JWE Ciphertext) gives this value:

  KDlTtXchhZTGufMYmOYGS4HffxPSUrfmqCHXaI9wOGY

Encoding this JWE Authentication Tag as BASE64URL(JWE Authentication Tag) gives this value:

  U0m_YmjN04DJvceFICbCVQ

A.3.7. Complete Representation

Assemble the final representation: The Compact Serialization of this result is the string BASE64URL(UTF8(JWE Protected Header)) || '.' || BASE64URL(JWE Encrypted Key) || '.' || BASE64URL(JWE Initialization Vector) || '.' || BASE64URL(JWE Ciphertext) || '.' || BASE64URL(JWE Authentication Tag).

The final result in this example (with line breaks for display purposes only) is:

  eyJhbGciOiJBMTI4S1ciLCJlbmMiOiJBMTI4Q0JDLUhTMjU2In0.
  6KB707dM9YTIgHtLvtgWQ8mKwboJW3of9locizkDTHzBC2IlrT1oOQ.
  AxY8DCtDaGlsbGljb3RoZQ.
  KDlTtXchhZTGufMYmOYGS4HffxPSUrfmqCHXaI9wOGY.
  U0m_YmjN04DJvceFICbCVQ

A.3.8. Validation

This example illustrates the process of creating a JWE with AES Key Wrap for key encryption and AES GCM for content encryption. These results can be used to validate JWE decryption implementations for these algorithms. Also, since both the AES Key Wrap and AES GCM computations are deterministic, the resulting JWE value will be the same for all encryptions performed using these inputs. Since the computation is reproducible, these results can also be used to validate JWE encryption implementations for these algorithms.

A.4. Example JWE using JWE JSON Serialization

This section contains an example using the JWE JSON Serialization. This example demonstrates the capability for encrypting the same plaintext to multiple recipients.

Two recipients are present in this example. The algorithm and key used for the first recipient are the same as that used in Appendix A.2. The algorithm and key used for the second recipient are the same as that used in Appendix A.3. The resulting JWE Encrypted Key values are therefore the same; those computations are not repeated here.

The Plaintext, the Content Encryption Key (CEK), Initialization Vector, and JWE Protected Header are shared by all recipients (which must be the case, since the Ciphertext and Authentication Tag are also shared).

A.4.1. JWE Per-Recipient Unprotected Headers

The first recipient uses the RSAES-PKCS1-V1_5 algorithm to encrypt the Content Encryption Key (CEK). The second uses AES Key Wrap to encrypt the CEK. Key ID values are supplied for both keys. The two per-recipient header values used to represent these algorithms and Key IDs are:

  {"alg":"RSA1_5","kid":"2011-04-29"}

and

  {"alg":"A128KW","kid":"7"}

A.4.2. JWE Protected Header

The Plaintext is encrypted using the AES_128_CBC_HMAC_SHA_256 algorithm to produce the common JWE Ciphertext and JWE Authentication Tag values. The JWE Protected Header value representing this is:

  {"enc":"A128CBC-HS256"}

Encoding this JWE Protected Header as BASE64URL(UTF8(JWE Protected Header)) gives this value:

  eyJlbmMiOiJBMTI4Q0JDLUhTMjU2In0

A.4.3. JWE Unprotected Header

This JWE uses the jku Header Parameter to reference a JWK Set. This is represented in the following JWE Unprotected Header value as:

  {"jku":"https://server.example.com/keys.jwks"}

A.4.4. Complete JWE Header Values

Combining the per-recipient, protected, and unprotected header values supplied, the JWE Header values used for the first and second recipient respectively are:

  {"alg":"RSA1_5",
   "kid":"2011-04-29",
   "enc":"A128CBC-HS256",
   "jku":"https://server.example.com/keys.jwks"}

and

  {"alg":"A128KW",
   "kid":"7",
   "enc":"A128CBC-HS256",
   "jku":"https://server.example.com/keys.jwks"}

A.4.5. Additional Authenticated Data

Let the Additional Authenticated Data encryption parameter be ASCII(BASE64URL(UTF8(JWE Protected Header))). This value is:

[101, 121, 74, 108, 98, 109, 77, 105, 79, 105, 74, 66, 77, 84, 73, 52, 81, 48, 74, 68, 76, 85, 104, 84, 77, 106, 85, 50, 73, 110, 48]

A.4.6. Content Encryption

Encrypt the Plaintext with AES_128_CBC_HMAC_SHA_256 using the CEK as the encryption key, the JWE Initialization Vector, and the Additional Authenticated Data value above. The steps for doing this using the values from Appendix A.3 are detailed in Appendix B. The resulting Ciphertext is:

[40, 57, 83, 181, 119, 33, 133, 148, 198, 185, 243, 24, 152, 230, 6, 75, 129, 223, 127, 19, 210, 82, 183, 230, 168, 33, 215, 104, 143, 112, 56, 102]

The resulting Authentication Tag value is:

[51, 63, 149, 60, 252, 148, 225, 25, 92, 185, 139, 245, 35, 2, 47, 207]

Encoding this JWE Ciphertext as BASE64URL(JWE Ciphertext) gives this value:

  KDlTtXchhZTGufMYmOYGS4HffxPSUrfmqCHXaI9wOGY

Encoding this JWE Authentication Tag as BASE64URL(JWE Authentication Tag) gives this value:

  Mz-VPPyU4RlcuYv1IwIvzw

A.4.7. Complete JWE JSON Serialization Representation

The complete JSON Web Encryption JSON Serialization for these values is as follows (with line breaks for display purposes only):

  {"protected":
    "eyJlbmMiOiJBMTI4Q0JDLUhTMjU2In0",
   "unprotected":
    {"jku":"https://server.example.com/keys.jwks"},
   "recipients":[
    {"header":
      {"alg":"RSA1_5"},
     "encrypted_key":
      "UGhIOguC7IuEvf_NPVaXsGMoLOmwvc1GyqlIKOK1nN94nHPoltGRhWhw7Zx0-
       kFm1NJn8LE9XShH59_i8J0PH5ZZyNfGy2xGdULU7sHNF6Gp2vPLgNZ__deLKx
       GHZ7PcHALUzoOegEI-8E66jX2E4zyJKx-YxzZIItRzC5hlRirb6Y5Cl_p-ko3
       YvkkysZIFNPccxRU7qve1WYPxqbb2Yw8kZqa2rMWI5ng8OtvzlV7elprCbuPh
       cCdZ6XDP0_F8rkXds2vE4X-ncOIM8hAYHHi29NX0mcKiRaD0-D-ljQTP-cFPg
       wCp6X-nZZd9OHBv-B3oWh2TbqmScqXMR4gp_A"},
    {"header":
      {"alg":"A128KW"},
     "encrypted_key":
      "6KB707dM9YTIgHtLvtgWQ8mKwboJW3of9locizkDTHzBC2IlrT1oOQ"}],
   "iv":
    "AxY8DCtDaGlsbGljb3RoZQ",
   "ciphertext":
    "KDlTtXchhZTGufMYmOYGS4HffxPSUrfmqCHXaI9wOGY",
   "tag":
    "Mz-VPPyU4RlcuYv1IwIvzw"
  }

Appendix B. Example AES_128_CBC_HMAC_SHA_256 Computation

This example shows the steps in the AES_128_CBC_HMAC_SHA_256 authenticated encryption computation using the values from the example in Appendix A.3. As described where this algorithm is defined in Sections 4.8 and 4.8.3 of JWA, the AES_CBC_HMAC_SHA2 family of algorithms are implemented using Advanced Encryption Standard (AES) in Cipher Block Chaining (CBC) mode with PKCS #5 padding to perform the encryption and an HMAC SHA-2 function to perform the integrity calculation - in this case, HMAC SHA-256.

B.1. Extract MAC_KEY and ENC_KEY from Key

The 256 bit AES_128_CBC_HMAC_SHA_256 key K used in this example is:

[4, 211, 31, 197, 84, 157, 252, 254, 11, 100, 157, 250, 63, 170, 106, 206, 107, 124, 212, 45, 111, 107, 9, 219, 200, 177, 0, 240, 143, 156, 44, 207]

Use the first 128 bits of this key as the HMAC SHA-256 key MAC_KEY, which is:

[4, 211, 31, 197, 84, 157, 252, 254, 11, 100, 157, 250, 63, 170, 106, 206]

Use the last 128 bits of this key as the AES CBC key ENC_KEY, which is:

[107, 124, 212, 45, 111, 107, 9, 219, 200, 177, 0, 240, 143, 156, 44, 207]

Note that the MAC key comes before the encryption key in the input key K; this is in the opposite order of the algorithm names in the identifiers "AES_128_CBC_HMAC_SHA_256" and A128CBC-HS256.

B.2. Encrypt Plaintext to Create Ciphertext

Encrypt the Plaintext with AES in Cipher Block Chaining (CBC) mode using PKCS #5 padding using the ENC_KEY above. The Plaintext in this example is:

[76, 105, 118, 101, 32, 108, 111, 110, 103, 32, 97, 110, 100, 32, 112, 114, 111, 115, 112, 101, 114, 46]

The encryption result is as follows, which is the Ciphertext output:

[40, 57, 83, 181, 119, 33, 133, 148, 198, 185, 243, 24, 152, 230, 6, 75, 129, 223, 127, 19, 210, 82, 183, 230, 168, 33, 215, 104, 143, 112, 56, 102]

B.3. 64 Bit Big Endian Representation of AAD Length

The Additional Authenticated Data (AAD) in this example is:

[101, 121, 74, 104, 98, 71, 99, 105, 79, 105, 74, 66, 77, 84, 73, 52, 83, 49, 99, 105, 76, 67, 74, 108, 98, 109, 77, 105, 79, 105, 74, 66, 77, 84, 73, 52, 81, 48, 74, 68, 76, 85, 104, 84, 77, 106, 85, 50, 73, 110, 48]

This AAD is 51 bytes long, which is 408 bits long. The octet string AL, which is the number of bits in AAD expressed as a big endian 64 bit unsigned integer is:

[0, 0, 0, 0, 0, 0, 1, 152]

B.4. Initialization Vector Value

The Initialization Vector value used in this example is:

[3, 22, 60, 12, 43, 67, 104, 105, 108, 108, 105, 99, 111, 116, 104, 101]

B.5. Create Input to HMAC Computation

Concatenate the AAD, the Initialization Vector, the Ciphertext, and the AL value. The result of this concatenation is:

[101, 121, 74, 104, 98, 71, 99, 105, 79, 105, 74, 66, 77, 84, 73, 52, 83, 49, 99, 105, 76, 67, 74, 108, 98, 109, 77, 105, 79, 105, 74, 66, 77, 84, 73, 52, 81, 48, 74, 68, 76, 85, 104, 84, 77, 106, 85, 50, 73, 110, 48, 3, 22, 60, 12, 43, 67, 104, 105, 108, 108, 105, 99, 111, 116, 104, 101, 40, 57, 83, 181, 119, 33, 133, 148, 198, 185, 243, 24, 152, 230, 6, 75, 129, 223, 127, 19, 210, 82, 183, 230, 168, 33, 215, 104, 143, 112, 56, 102, 0, 0, 0, 0, 0, 0, 1, 152]

B.6. Compute HMAC Value

Compute the HMAC SHA-256 of the concatenated value above. This result M is:

[83, 73, 191, 98, 104, 205, 211, 128, 201, 189, 199, 133, 32, 38, 194, 85, 9, 84, 229, 201, 219, 135, 44, 252, 145, 102, 179, 140, 105, 86, 229, 116]

B.7. Truncate HMAC Value to Create Authentication Tag

Use the first half (128 bits) of the HMAC output M as the Authentication Tag output T. This truncated value is:

[83, 73, 191, 98, 104, 205, 211, 128, 201, 189, 199, 133, 32, 38, 194, 85]

Appendix C. Acknowledgements

Solutions for encrypting JSON content were also explored by JSON Simple Encryption [JSE] and JavaScript Message Security Format [I-D.rescorla-jsms], both of which significantly influenced this draft. This draft attempts to explicitly reuse as many of the relevant concepts from XML Encryption 1.1 [W3C.CR-xmlenc-core1-20120313] and RFC 5652 [RFC5652] as possible, while utilizing simple, compact JSON-based data structures.

Special thanks are due to John Bradley and Nat Sakimura for the discussions that helped inform the content of this specification and to Eric Rescorla and Joe Hildebrand for allowing the reuse of text from [I-D.rescorla-jsms] in this document.

Thanks to Axel Nennker, Emmanuel Raviart, Brian Campbell, and Edmund Jay for validating the examples in this specification.

This specification is the work of the JOSE Working Group, which includes dozens of active and dedicated participants. In particular, the following individuals contributed ideas, feedback, and wording that influenced this specification:

Richard Barnes, John Bradley, Brian Campbell, Breno de Medeiros, Dick Hardt, Jeff Hodges, Edmund Jay, James Manger, Matt Miller, Tony Nadalin, Axel Nennker, Emmanuel Raviart, Nat Sakimura, Jim Schaad, Hannes Tschofenig, and Sean Turner.

Jim Schaad and Karen O'Donoghue chaired the JOSE working group and Sean Turner and Stephen Farrell served as Security area directors during the creation of this specification.

Appendix D. Document History

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Authors' Addresses

Michael B. Jones Microsoft EMail: mbj@microsoft.com URI: http://self-issued.info/
Eric Rescorla RTFM, Inc. EMail: ekr@rtfm.com
Joe Hildebrand Cisco Systems, Inc. EMail: jhildebr@cisco.com