draft-ietf-mmusic-kmgmt-ext-04.txt   draft-ietf-mmusic-kmgmt-ext-05.txt 
Internet Engineering Task Force J. Arkko Internet Engineering Task Force J. Arkko
MMUSIC Working Group E. Carrara MMUSIC Working Group E. Carrara
INTERNET-DRAFT F. Lindholm INTERNET-DRAFT F. Lindholm
Expires: October 2002 M. Naslund Expires: December 2002 M. Naslund
K. Norrman K. Norrman
Ericsson Ericsson
April, 2002 June, 2002
Key Management Extensions for SDP and RTSP Key Management Extensions for SDP and RTSP
<draft-ietf-mmusic-kmgmt-ext-04.txt> <draft-ietf-mmusic-kmgmt-ext-05.txt>
Status of this memo Status of this memo
This document is an Internet-Draft and is in full conformance with This document is an Internet-Draft and is in full conformance with
all provisions of Section 10 of RFC2026. all provisions of Section 10 of RFC2026.
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF), its areas, and its working groups. Note that other Task Force (IETF), its areas, and its working groups. Note that other
groups may also distribute working documents as Internet-Drafts. groups may also distribute working documents as Internet-Drafts.
skipping to change at page 2, line 14 skipping to change at page 2, line 14
TABLE OF CONTENTS TABLE OF CONTENTS
1. Introduction.....................................................2 1. Introduction.....................................................2
1.1. Notational Conventions.........................................3 1.1. Notational Conventions.........................................3
2. Extensions to SDP and RTSP.......................................3 2. Extensions to SDP and RTSP.......................................3
2.1. SDP Extensions.................................................4 2.1. SDP Extensions.................................................4
2.2. RTSP Extensions................................................4 2.2. RTSP Extensions................................................4
3. Usage with SIP and RTSP..........................................5 3. Usage with SIP and RTSP..........................................5
3.1. General SDP processing.........................................5 3.1. General SDP processing.........................................5
3.2. SIP usage......................................................6 3.2. SIP usage......................................................7
3.3. RTSP usage.....................................................7 3.3. RTSP usage.....................................................7
3.4. Example scenarios..............................................7 3.4. Example scenarios..............................................8
4. Adding a Key management protocol.................................9 4. Adding further Key management protocols.........................10
5. Security Considerations.........................................10 5. Security Considerations.........................................10
6. IANA Considerations.............................................10 6. IANA Considerations.............................................11
7. Conclusions.....................................................10 7. Conclusions.....................................................11
8. Acknowledgments.................................................11 8. Acknowledgments.................................................11
9. Author's Addresses..............................................11 9. Author's Addresses..............................................11
10. References.....................................................11 10. References.....................................................12
10.1. Normative References.........................................11 10.1. Normative References.........................................12
10.2. Informative References.......................................12 10.2. Informative References.......................................12
1. Introduction 1. Introduction
There has recently been work to define a security framework for the There has recently been work to define a security framework for the
protection of real-time applications running over RTP, [SRTP]. protection of real-time applications running over RTP, [SRTP].
However, a security protocol needs a key management infrastructure to However, a security protocol needs a key management infrastructure to
exchange keys and security parameters, managing and refreshing keys, exchange keys and security parameters, managing and refreshing keys,
etc. etc.
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decode the audio (or video) stream, the key management data is a decode the audio (or video) stream, the key management data is a
description of how to encrypt and decrypt the data. description of how to encrypt and decrypt the data.
* The possibility to negotiate the security for the entire multimedia * The possibility to negotiate the security for the entire multimedia
session at the same time. session at the same time.
* The knowledge of the media at the session establishment makes it * The knowledge of the media at the session establishment makes it
easy to tie the key management to the multimedia sessions. easy to tie the key management to the multimedia sessions.
* This approach may be more efficient than setting up the security * This approach may be more efficient than setting up the security
later, as that approach might force extra roundtrips, possibly also later, as that approach might force extra roundtrips, possibly
a separate set-up for each stream, hence implying more delay to the also a separate set-up for each stream, hence implying more delay
actual setup of the media session. to the actual setup of the media session.
Currently in SDP [SDPnew], one field exists to transport keys, i.e. Currently in SDP [SDPnew], one field exists to transport keys, i.e.
the "key=" field. However, this is not enough for a key management the "key=" field. However, this is not enough for a key management
protocol. The approach here is to use and extend the SDP description protocol. The approach here is to use and extend the SDP description
to transport the key management offer/answer and also to associate it to transport the key management offer/answer and also to associate it
with the media sessions. SIP uses the offer/answer model [OAM] with the media sessions. SIP uses the offer/answer model [OAM]
whereby extensions to SDP will be enough. An extra RTSP header is whereby extensions to SDP will be enough. However, RTSP [RTSP] does
also defined. not use the offer/answer model. This makes it impossible to send back
an answer to the server. To solve this, a new header is introduced in
which the key management data can be included.
1.1. Notational Conventions 1.1. Notational Conventions
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC-2119. document are to be interpreted as described in RFC-2119.
2. Extensions to SDP and RTSP 2. Extensions to SDP and RTSP
This section describes common attributes that are to be included in This section describes common attributes that are to be included in
an SDP description or in an RTSP header when an integrated key an SDP description or in an RTSP header when an integrated key
management protocol is used. The attribute values MUST follow the management protocol is used. The attribute values MUST follow the
general SDP or RTSP guideline. general SDP or RTSP guidelines.
For the SDP description, the key management attributes may be defined For the SDP description, the key management attributes MAY be defined
at session level (i.e. before the media descriptor lines) and/or at at session level (i.e. before the media descriptor lines) and/or at
media level. If the key management attributes are defined at media media level. If the key management attributes are defined at media
level, they will only apply to that specific media. If the key level, they will only apply to that specific media. If the key
management attributes are defined at both session and media level, management attributes are defined at both session and media level,
the media level definition overrides the session level definition for the media level definition overrides the session level definition for
that specific media. that specific media.
The following SDP attribute is defined: The following SDP attribute is defined:
key-mgmt:<name> <opaque-data> key-mgmt:<name> <opaque-data>
<name> is the name of the key management protocol and the opaque-data <name> is the name of the key management protocol and the opaque-data
is a field to transport the key management protocol data. The key is a field to transport the key management protocol data. The key
management protocol data contains the necessary information to management protocol data contains the necessary information to
establish the security protocol, e.g., keys and cryptographic establish the security protocol, e.g., keys and cryptographic
parameters. All parameters and keys are protected by the key parameters. All parameters and keys are protected by the key
management. Note that if the key management protocol fails, e.g., the management. Note that if the key management protocol fails, e.g., the
receiver does not accept any of the proposed security parameters, or receiver does not accept any of the proposed security parameters, or
simply does not understand the key management protocol, the security simply does not understand the key management protocol, the security
setup will fail. Consequently, it is impossible to establish a secure setup will fail. Consequently, it is impossible to establish a secure
session. This is very similar to the normal SIP/SDP behavior: if the session. So, if the key management fails, the offer must be rejected.
sender supports codecs which are not supported by the receiver, it
will be problematic to set up a session.
2.1. SDP Extensions 2.1. SDP Extensions
This section provides an Augmented Backus-Naur Form (ABNF) grammar This section provides an Augmented Backus-Naur Form (ABNF) grammar
(as used in [SDPnew]) for the key management extensions to SDP. (as used in [SDPnew]) for the key management extensions to SDP.
Note that the new definitions are compliant with the definition of an Note that the new definitions are compliant with the definition of an
attribute field, i.e. attribute field, i.e.
attribute = (att-field ":" att-value) | att-field attribute = (att-field ":" att-value) | att-field
One new attribute for SDP is defined: One new attribute for SDP is defined:
key-mgmt = "key-mgmt:" prtcl-name keymgmt-data key-mgmt = "key-mgmt:" prtcl-name keymgmt-data
prtcl-name = non-ws-string prtcl-name = non-ws-string
; e.g. "MIKEY" ; e.g. "MIKEY"
keymgmt-data = byte-string keymgmt-data = text
where non-ws-string and byte-string are as defined in SDP [SDPnew]. where non-ws-string and text are as defined in SDP [SDPnew]. The
attribute may be used at session level, media level or at both
levels. An attribute defined at media level overrides an attribute
defined at session level.
2.2. RTSP Extensions 2.2. RTSP Extensions
To support the needed attribute described, the following RTSP header To support the needed attribute described, the following RTSP header
is defined: is defined:
KeyMgmt _ "keymgmt" ":" "prot" "=" token ";" "data" "=" quoted-string KeyMgmt _ "keymgmt" ":" 1#key-mgmt-spec
key-mgmt-spec _ "prot" "=" token ";" "data" "=" quoted-string
token and quoted-string are as defined in the RTSP specification token and quoted-string are as defined in the RTSP specification
[RTSP]. [RTSP].
The KeyMgmt header should be possible to use in both request and The KeyMgmt header should be possible to use in the messages
response messages of the following methods: described in the table below.
* DESCRIBE Method Direction Requirement
* ANNOUNCE DESCRIBE C->S required
* SETUP SETUP C->S required
ANNOUNCE C->S, S->C optional (required: if re-key should
be supported)
3. Usage with SIP and RTSP 3. Usage with SIP and RTSP
This section gives recommendations of how/when to include the defined This section gives recommendations of how/when to include the defined
key management attribute when SIP and/or RTSP are used together with key management attribute when SIP and/or RTSP are used together with
SDP. SDP.
Some general requirements are set on a key management protocol (and When a key management protocol is integrated with SIP/SDP and RTSP,
its API) when used within SIP and RTSP: the following requirements are put on the key management:
* It MUST be possible to execute the key management protocol in at * It MUST be possible to execute the key management protocol in at
most one roundtrip in case the answerer accepts the offer. most one roundtrip in case the answerer accepts the offer.
* It MUST be possible, using the key management API, to receive a * It MUST be possible from the SIP/SDP and RTSP application, using
valid offer/answer and whether the provided offer was accepted or the key management API, to receive key management data, and
not. information of whether a message is accepted or not.
Today, the MIKEY protocol [MIKEY] has adopted the key management Today, the MIKEY protocol [MIKEY] has adopted the key management
extensions to work together with SIP and RTSP. Other protocols may extensions to work together with SIP and RTSP. Other protocols MAY
use the described attribute and header, e.g. Kerberos [KERB]. use the described attribute and header, e.g. Kerberos [KERB].
3.1. General SDP processing 3.1. General SDP processing
When an SDP message is created, the following procedure should be When an SDP message is created, the following procedure should be
applied: applied:
* The identifier of the key management protocol used (e.g. MIKEY or * The identifier of the key management protocol used (e.g. MIKEY or
Kerberos) is put in the prtcl-name field. Kerberos) MUST be put in the prtcl-name field.
* The keymgmt-data field is created by the data received from the key * The keymgmt-data field MUST be created with the data received from
management protocol API. The data may e.g. be a MIKEY message or the key management protocol (this data MUST be base64 encoded).
Kerberos ticket. The data may e.g. be a MIKEY message or Kerberos ticket.
A received SDP message that contains the key management attributes A received SDP message that contains the key management attributes
SHOULD process these attributes in the following manner: SHOULD process these attributes in the following manner:
* Detect the key management protocol used by checking the prtcl-name * The key management protocol used MUST be identified by checking the
field in the key management attribute. prtcl-name field in the key management attribute.
* Extract the key management data from the keymgmt-data field and * The key management data from the keymgmt-data field MUST be
call the key management protocol with the extracted data. Note that extracted and given to the key management protocol. Note that
depending on key management protocol, some extra parameters might depending on key management protocol, some extra parameters might
of course be requested, such as the source/destination network of course be requested, such as the source/destination network
address/port(s) for the specified media. address/port(s) for the specified media.
* Depending on the outcome of the key management processing (i.e. * Depending on the outcome of the key management processing (i.e.
whether it was accepted or not), the processing can proceed whether it was accepted or not), the processing can proceed
according to normal processing (e.g. according to the offer/answer according to normal processing (e.g. according to the offer/answer
model, see also Section 3.2). model, see also Section 3.2).
If more than one key management protocol are supported, multiple Note that the attribute MAY be repeated more than once (e.g., one at
instance of the key management attribute MAY be included in the session level and one at media level). Consequently, the process is
initial offer, each transporting a different key management data. repeated for each key management attribute detected.
If more than one key management protocol is supported, multiple
instances of the key management attribute MAY be included in the
initial offer, each transporting a different key management data,
thus indicating alternatives supported.
If the sender includes more than one key management attributes at
session level (analogous for the media level), these SHOULD be listed
in order of preference (with the first being the preferred). The
receiver chooses the key management protocol it supports. When
answering, only the accepted key management attribute MUST be
included. If the receiver does not support any of the sender's
suggested key management protocols, the receiver answers with an
error message (see SIP and RTSP), possibly also listing the supported
key management protocols (without any data included).
However, the offerer is RECOMMENDED to include only one of the However, the offerer is RECOMMENDED to include only one of the
protocols for a specific media. If the answerer cannot support the protocols for a specific media. If the answerer cannot support the
proposed protocol, it rejects the offer. Placing multiple key proposed protocol, it rejects the offer.
management offers in a single message would have the disadvantage
that the message expands and the computational workload for the Note that by placing multiple key management offers in a single
offerer will increase drastically. It might be acceptable to use a message has the disadvantage that the message expands and the
trial and error approach if the number of key management protocols computational workload for the offerer will increase drastically. It
supported are few. The possibility to support multiple key management might be acceptable to use a trial and error approach if the number
protocols may introduce bidding down attacks. It is therefore of key management protocols supported are few. The possibility to
important that the local policy considers this (e.g., only allows support multiple key management protocols may introduce bidding down
protocols that from a security point of view are equivalent, to be attacks. It is therefore important that the local policy considers
negotiated). this (e.g., only allows protocols that from a security point of view
are equivalent, to be negotiated).
What can be done to increase the likelihood for a successful setup is What can be done to increase the likelihood for a successful setup is
to use a capability discovery mechanism (e.g., used in SIP). In this to use a capability discovery mechanism (e.g., used in SIP when using
case, the key management protocols supported are expressed at session the OPTION message). In this case, the key management protocols
level without any data (i.e., a list of only the key-mgmt:<name> part supported are expressed at session level without any data (i.e., a
is used). list of only the key-mgmt:<name> part is used).
v=0 v=0
o=alice 2891092738 2891092738 IN IP4 lost.somewhere.com o=alice 2891092738 2891092738 IN IP4 lost.somewhere.com
c=IN IP4 lost.somewhere.com c=IN IP4 lost.somewhere.com
a=key-mgmt:mikey a=key-mgmt:mikey
a=key-mgmt:coolxchg a=key-mgmt:coolxchg
m=audio 0 RTP/SAVP 98 m=audio 0 RTP/SAVP 98
a=rtpmap:98 AMR/8000 a=rtpmap:98 AMR/8000
m=video 0 RTP/SAVP 31 34 m=video 0 RTP/SAVP 31 34
a=rtpmap:31 H261/90000 a=rtpmap:31 H261/90000
a=rtpmap:34 H263/90000 a=rtpmap:34 H263/90000
3.2. SIP usage 3.2. SIP usage
The offerer SHOULD include the key management data within an offer The offerer SHOULD include the key management data within an offer
that contains the media description it should apply to. The answerer that contains the media description it should apply to. The answerer
MUST check with the key management protocol if the attribute values MUST check with the key management protocol if the attribute values
are valid, and then obtain from the key management the data to are valid, and then obtain from the key management the data to
include in the answer. If the offer is not accepted, the answerer include in the answer.
returns a notification message and the offerer may go out with a new
(different) offer, depending on the local security policy. If the offer is not accepted, the answerer SHOULD return a "606 Not
Acceptable" message, including one or more Warning headers (at least
a 306). The offerer MAY then go out with a new (different) offer,
depending on the local security policy.
Re-keying can be handled as a new offer, i.e. a re-INVITE should be Re-keying can be handled as a new offer, i.e. a re-INVITE should be
sent with the new proposed parameters. The answerer treats this as a sent with the new proposed parameters. The answerer treats this as a
new offer where the key management is the issue of change. new offer where the key management is the issue of change. In
general, the re-INVITE (and the key exchange) must be finalized
before the security protocol can change the keys. The synchronization
method used when changing keys are dependent on the security and key
management protocol used.
3.3. RTSP usage 3.3. RTSP usage
RTSP does not use the offer/answer model, as SIP does. This causes RTSP does not use the offer/answer model, as SIP does. This causes
some problems as it is not possible (without abusing RTSP) to send some problems as it is not possible (without abusing RTSP) to send
back an answer to the server (as the server will in most cases be the back an answer to the server (as the server will in most cases be the
one initiating the security parameter exchange). To solve this, a new one initiating the security parameter exchange). To solve this, a new
header has been introduced (Section 2.2). This also assumes that the header has been introduced (Section 2.2). This also assumes that the
key management also have some kind of binding to the media, so that key management also have some kind of binding to the media, so that
the response to the server will be processed as required. the response to the server will be processed as required.
The processing of a key management header in RTSP should be done The processing of a key management header in RTSP should be done
analogous of the SDP message processing. The initial key management analogous of the SDP message processing. The initial key management
message from a server should be sent to the client using SDP. When message from a server should be sent to the client using SDP. When
responding to this, the client uses the new RTSP header to send back responding to this, the client uses the new RTSP header to send back
an answer (included in the SETUP message). If the server retrieves a an answer (included in the SETUP message). If a server receives a
SETUP message in which it expects a key management message, but none SETUP message in which it expects a key management message, but none
is included, a 403 Forbidden is returned to the client. is included, a 403 Forbidden SHOULD be returned to the client.
The server may provide re-keying/updating facilities by sending a new The server MAY provide re-keying/updating facilities by sending a new
key management message in an ANNOUNCE messages. The ANNOUNCE message key management message in an ANNOUNCE messages. The ANNOUNCE message
contains an SDP message including the key management parameters. The contains an SDP message including the key management parameters. The
response message is put in the new RTSP header in the response from response message is put in the new RTSP header in the response from
the client to the server. Note that the ANNOUNCE messages MUST be the client to the server. Note that the ANNOUNCE messages MUST be
supported if this feature are to be used. supported if this feature is to be used.
3.4. Example scenarios 3.4. Example scenarios
Example 1 (SIP) Example 1 (SIP)
A SIP call is taking place between Alice and Bob. Alice sends an A SIP call is taking place between Alice and Bob. Alice sends an
Invite message consisting of the following offer: Invite message consisting of the following offer:
v=0 v=0
o=alice 2891092738 2891092738 IN IP4 lost.somewhere.com o=alice 2891092738 2891092738 IN IP4 lost.somewhere.com
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Example 3 (RTSP) Example 3 (RTSP)
A client wants to set up a streaming session and requests a media A client wants to set up a streaming session and requests a media
description from the streaming server. description from the streaming server.
DESCRIBE rtsp://server.example.com/fizzle/foo RTSP/1.0 DESCRIBE rtsp://server.example.com/fizzle/foo RTSP/1.0
CSeq: 312 CSeq: 312
Accept: application/sdp Accept: application/sdp
From: user@client.com From: user@client.com
The server sends back an OK message including a SDP description. The server sends back an OK message including an SDP description.
RTSP/1.0 200 OK RTSP/1.0 200 OK
CSeq: 312 CSeq: 312
Date: 23 Jan 1997 15:35:06 GMT Date: 23 Jan 1997 15:35:06 GMT
Content-Type: application/sdp Content-Type: application/sdp
v=0 v=0
o=actionmovie 2891092738 2891092738 IN IP4 movie.somewhere.com o=actionmovie 2891092738 2891092738 IN IP4 movie.somewhere.com
s=Action Movie s=Action Movie
e=action@movie.somewhere.com e=action@movie.somewhere.com
t=0 0 t=0 0
c=IN IP4 movie.somewhere.com c=IN IP4 movie.somewhere.com
a=key-mgmt:mikey uiSDF9sdhs727ghsd/dhsoKkdOokdo7eWsnDSJD... a=key-mgmt:mikey uiSDF9sdhs727ghsd/dhsoKkdOokdo7eWsnDSJD...
m=audio 0 RTP/SAVP 98 m=audio 0 RTP/SAVP 98
a=rtpmap:98 AMR/8000 a=rtpmap:98 AMR/8000
control:rtsp://movie.somewhere.com/action/audio control:rtsp://movie.somewhere.com/action/audio
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RTSP/1.0 200 OK RTSP/1.0 200 OK
CSeq: 313 CSeq: 313
Session: 12345678 Session: 12345678
Transport: RTP/SAVP/UDP;unicast;client_port=3056-3057; Transport: RTP/SAVP/UDP;unicast;client_port=3056-3057;
server_port=5000-5001 server_port=5000-5001
The RTSP then proceeds as usual (with e.g. a SETUP message for the The RTSP then proceeds as usual (with e.g. a SETUP message for the
video followed by a PLAY message). video followed by a PLAY message).
4. Adding a Key management protocol 4. Adding further Key management protocols
This framework can not be used with all key management protocols. The This framework can not be used with all key management protocols. The
key management protocol needs to comply with the requirements key management protocol needs to comply with the requirements
described in Section 3. To be able to use a key management protocol described in Section 3. To be able to use a key management protocol
with this framework, the following needs to be specified: with this framework, the following MUST be specified:
* the key management protocol name that should be used in the * the key management protocol name that should be used in the
protocol name fields in both SDP and RTSP (e.g. "mikey" for MIKEY). protocol name fields in both SDP and RTSP (e.g. "mikey" for
MIKEY).
* the information the key management needs from SDP and RTSP (Section * the information the key management needs from SDP and RTSP (Section
3 gives a guideline of what SDP and RTSP needs from the key 3 gives a guideline of what SDP and RTSP needs from the key
management). The exact API is implementation specific, but it management). The exact API is implementation specific, but it
SHOULD at least support to exchange the specified information. SHOULD at least support to exchange the specified information.
The encoding of the data MUST be specified for each key management The key management data MUST be base64 encoded in the SDP and RTSP
protocol and comply with the SDP and RTSP definitions. For most fields. Therefore, considerations of possible conversion from the
protocols, base64 encoding will be most appropriate. normal key management representation to base64 SHOULD be taken into
consideration.
5. Security Considerations 5. Security Considerations
The nature of this document is to allow SDP and RTSP to support The nature of this document is to allow SDP and RTSP to support
security of the media sessions. It is therefore not the intention of security of the media sessions. It is therefore not the intention of
this document to describe possible security solution or to define this document to describe possible security solutions or to define
possible security problems. The defined SDP and RTSP extensions are possible security problems. The defined SDP and RTSP extensions are
not believed to introduce any new security risks to SDP and RTSP. not believed to introduce any new security risks to SDP and RTSP.
Note that the purpose of the key management fields is to provide Note that the purpose of the key management fields is to provide
information to secure the media streams. Under the assumption that information to secure the media streams. Under the assumption that
the key management schemes are secure, the SDP can be passed along the key management schemes are secure, the SDP can be passed along
unprotected without affecting the key management, and the media unprotected without affecting the key management, and the media
streams will still be secure even if some attackers gained knowledge streams will still be secure even if some attackers gained knowledge
of the SDP contents. of the SDP contents.
However, if the SDP messages are not sent authenticated between the However, if the SDP messages are not sent authenticated between the
parties, it is possible for an active attacker to change attributes parties, it is possible for an active attacker to change attributes
without being detected. As the key management protocol may (indirect) without being detected. As the key management protocol may
rely on some of the session information from SDP (e.g., address (indirectly) rely on some of the session information from SDP (e.g.,
information), an attack on SDP may give indirect consequences on the address information), an attack on SDP may have indirect consequences
key management. In general, it is therefore a good thing, not only to on the key management. In general, it is therefore a good thing, not
try to secure the session, but also to secure the session setup. only to try to secure the session, but also to secure the session
setup.
6. IANA Considerations 6. IANA Considerations
New attribute fields for SDP (see Section 2.1) and RTSP header are New attribute fields for SDP (see Section 2.1) and RTSP header are
registered (see Section 2.2). registered (see Section 2.2).
7. Conclusions 7. Conclusions
A security solution for real-time applications needs a key management A security solution for real-time applications needs a key management
infrastructure. Integrating the key management scheme with the infrastructure. Integrating the key management scheme with the
skipping to change at page 12, line 21 skipping to change at page 12, line 44
Service (V5)", IETF, RFC 1510. Service (V5)", IETF, RFC 1510.
[MIKEY] Arkko, J., Carrara, E., Lindholm, F., Naslund, M., and [MIKEY] Arkko, J., Carrara, E., Lindholm, F., Naslund, M., and
Norrman, K., "MIKEY: Multimedia Internet KEYing", Internet Draft, Norrman, K., "MIKEY: Multimedia Internet KEYing", Internet Draft,
IETF, Work in progress (MSEC). IETF, Work in progress (MSEC).
[SRTP] Baugher, M., Blom, R., Carrara, E., McGrew, D., Naslund, M, [SRTP] Baugher, M., Blom, R., Carrara, E., McGrew, D., Naslund, M,
Norrman, K., and Oran, D., "The Secure Real Time Transport Protocol", Norrman, K., and Oran, D., "The Secure Real Time Transport Protocol",
Internet Draft, IETF, Work in Progress (AVT). Internet Draft, IETF, Work in Progress (AVT).
This Internet-Draft expires in October 2002. This Internet-Draft expires in December 2002.
 End of changes. 

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