draft-ietf-smime-idea-07.txt   rfc3058.txt 
Internet Draft S. Teiwes,
draft-ietf-smime-idea-07.txt P. Hartmann,
August 30, 2000 D. Kuenzi
Expires in six months iT_Security AG (Ltd.)
Use of the IDEA Encryption Algorithm in CMS Network Working Group S. Teiwes
Request for Comments: 3058 P. Hartmann
Category:Informational iT_Security AG (Ltd.)
D. Kuenzi
724 Solutions Inc.
February 2001
Use of the IDEA Encryption Algorithm in CMS
Status of this Memo Status of this Memo
This document is an Internet-Draft and is in full conformance with This memo provides information for the Internet community. It does
all provisions of section 10 of RFC2026. Internet-Drafts are not specify an Internet standard of any kind. Distribution of this
working documents of the Internet Engineering Task Force (IETF), memo is unlimited.
its areas, and its working groups. Note that other groups may also
distribute working documents as Internet-Drafts.
Internet-Drafts are draft documents valid for a maximum of six Copyright Notice
months and may be updated, replaced, or obsoleted by other documents
at any time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
The list of current Internet-Drafts can be accessed at Copyright (C) The Internet Society (2001). All Rights Reserved.
http://www.ietf.org/ietf/1id-abstracts.txt
The list of Internet-Draft Shadow Directories can be accessed at Abstract
http://www.ietf.org/shadow.html.
To view the entire list of current Internet-Drafts, please check the This memo specifies how to incorporate International Data Encryption
"1id-abstracts.txt" listing contained in the Internet-Drafts Shadow Algorithm (IDEA) into CMS or S/MIME as an additional strong algorithm
Directories on ftp.is.co.za (Africa), ftp.nordu.net (Northern for symmetric encryption. For organizations who make use of IDEA for
Europe), ftp.nis.garr.it (Southern Europe), munnari.oz.au (Pacific data security purposes it is of high interest that IDEA is also
Rim), ftp.ietf.org (US East Coast), or ftp.isi.edu (US West Coast). available in S/MIME. The intention of this memo is to provide the
OIDs and algorithms required that IDEA can be included in S/MIME for
symmetric content and key encryption.
1. Introduction 1. Introduction
This memo specifies how to incorporate IDEA (International Data This memo specifies how to incorporate International Data Encryption
Encryption Algorithm) [IDEA] into CMS or S/MIME [SMIME2, SMIME3] Algorithm (IDEA) [IDEA] into CMS or S/MIME [SMIME2, SMIME3] as an
as an additional strong algorithm for symmetric encryption. For additional strong algorithm for symmetric encryption. For
organizations who make use of IDEA for data security purposes organizations who make use of IDEA for data security purposes it is
it is required that IDEA is also available in S/MIME. of high interest that IDEA is also available in S/MIME. The
The intention of this memo is to provide the OIDs and algorithms intention of this memo is to provide the OIDs and algorithms required
required that IDEA can be included in S/MIME for symmetric content that IDEA can be included in S/MIME for symmetric content and key
and key encryption. encryption.
The general functional capabilities and preferences of S/MIME are The general functional capabilities and preferences of S/MIME are
specified by the registered list of S/MIME object identifiers (OIDs). specified by the registered list of S/MIME object identifiers (OIDs).
This list of OIDs is available from the Internet Mail Consortium at This list of OIDs is available from the Internet Mail Consortium at
<http://www.imc.org/ietf-smime/oids.html>. <http://www.imc.org/ietf-smime/oids.html>. The set of S/MIME
The set of S/MIME functions provided by a client is expressed by the functions provided by a client is expressed by the S/MIME
S/MIME capabilities attribute. This attribute contains a list of OIDs capabilities attribute. This attribute contains a list of OIDs of
of supported cryptographic functions. supported cryptographic functions.
In this document, the terms MUST, MUST NOT, SHOULD, and SHOULD NOT In this document, the terms MUST, MUST NOT, SHOULD, and SHOULD NOT
are used in capital letters. This conforms to the definitions in are used in capital letters. This conforms to the definitions in
[MUSTSHOULD]. [MUSTSHOULD].
2. Object Identifier for Content and Key Encryption 2. Object Identifier for Content and Key Encryption
The Cryptographic Message Syntax [CMS], derived from PKCS#7 [PKCS7], The Cryptographic Message Syntax [CMS], derived from PKCS#7 [PKCS7],
is the framework for the implementation of cryptographic functions in is the framework for the implementation of cryptographic functions in
S/MIME. It specifies data formats and encryption processes without S/MIME. It specifies data formats and encryption processes without
naming the cryptographic algorithms. Each algorithm which is used naming the cryptographic algorithms. Each algorithm which is used
for encryption purposes must be specified by a unique algorithm for encryption purposes must be specified by a unique algorithm
identifier. For example, in the special case of content encryption identifier. For example, in the special case of content encryption
the ContentEncryptionAlgorithmIdentifier specifies the algorithm to the ContentEncryptionAlgorithmIdentifier specifies the algorithm to
be applied. However, according to [CMS] any symmetric encryption be applied. However, according to [CMS] any symmetric encryption
algorithm that a CMS implementation includes as a content-encryption algorithm that a CMS implementation includes as a content-encryption
algorithm must also be included as a key-encryption algorithm. algorithm must also be included as a key-encryption algorithm.
IDEA is added to the set of optional symmetric encryption algorithms IDEA is added to the set of optional symmetric encryption algorithms
in S/MIME by providing two unique object identifiers (OIDs). One OID in S/MIME by providing two unique object identifiers (OIDs). One OID
defines content encryption and the other one key encryption. Thus an defines content encryption and the other one key encryption. Thus an
S/MIME agent can apply IDEA either for content or key encryption by S/MIME agent can apply IDEA either for content or key encryption by
selecting the corresponding object identifier, supplying the required selecting the corresponding object identifier, supplying the required
parameter, and starting the program code. parameter, and starting the program code.
For content encryption the use of IDEA in cipher block chaining (CBC) For content encryption the use of IDEA in cipher block chaining (CBC)
mode is recommended. The key length is fixed to 128 bits. mode is recommended. The key length is fixed to 128 bits.
The IDEA content-encryption algorithm in CBC mode has the object The IDEA content-encryption algorithm in CBC mode has the object
identifier identifier
IDEA-CBC OBJECT IDENTIFIER IDEA-CBC OBJECT IDENTIFIER
::= { iso(1) identified-organization(3) ::= { iso(1) identified-organization(3)
usdod(6) oid(1) private(4) enterprises(1) usdod(6) oid(1) private(4) enterprises(1)
ascom(188) systec(7) security(1) algorithms(1) 2 } ascom(188) systec(7) security(1) algorithms(1) 2 }
The identifier's parameters field contains the initialization The identifier's parameters field contains the initialization vector
vector (IV) as an optional parameter. (IV) as an optional parameter.
IDEA-CBCPar ::= SEQUENCE { IDEA-CBCPar ::= SEQUENCE {
iv OCTET STRING OPTIONAL } -- exactly 8 octets iv OCTET STRING OPTIONAL } -- exactly 8 octets
If IV is specified as above, it MUST be used as initial vector. In If IV is specified as above, it MUST be used as initial vector. In
this case, the ciphertext MUST NOT include the initial vector. If this case, the ciphertext MUST NOT include the initial vector. If IV
IV is not specified, the first 64 bits of the ciphertext MUST be is not specified, the first 64 bits of the ciphertext MUST be
considered as the initial vector. However, this alternative of not considered as the initial vector. However, this alternative of not
including the IV SHOULD NOT be applied in CMS or S/MIME. including IV into "iv OCTET STRING" of IDEA-CBCPar SHOULD NOT be
applied in CMS or S/MIME.
The key-wrap/unwrap algorithms used to encrypt/decrypt an IDEA The key-wrap/unwrap algorithms used to encrypt/decrypt an IDEA
content-encryption key with an IDEA key-encryption key are content-encryption key with an IDEA key-encryption key are specified
specified in the following section. Generation and distribution in the following section. Generation and distribution of IDEA key-
of IDEA key-encryption keys are beyond the scope of this document. encryption keys are beyond the scope of this document.
The IDEA key-encryption algorithm has the object identifier The IDEA key-encryption algorithm has the object identifier
id-alg-CMSIDEAwrap OBJECT IDENTIFIER id-alg-CMSIDEAwrap OBJECT IDENTIFIER
::= { iso(1) identified-organization(3) ::= { iso(1) identified-organization(3)
usdod(6) oid(1) private(4) enterprises(1) usdod(6) oid(1) private(4) enterprises(1)
ascom(188) systec(7) security(1) algorithms(1) 6 } ascom(188) systec(7) security(1) algorithms(1) 6 }
The identifier's parameters field MUST be NULL. The identifier's parameters field MUST be NULL.
3. Key-Wrapping and Unwrapping 3. Key-Wrapping and Unwrapping
In the following subsections IDEA key-wrap and key-unwrap algorithms In the following subsections IDEA key-wrap and key-unwrap algorithms
are specified in conformance with [CMS], section 12.3. are specified in conformance with [CMS], section 12.3.
3.1 IDEA Key Wrap 3.1 IDEA Key Wrap
The IDEA key-wrap algorithm encrypts an IDEA content-encryption key The IDEA key-wrap algorithm encrypts an IDEA content-encryption key
with an IDEA key-encryption key. The IDEA key-wrap algorithm is with an IDEA key-encryption key. The IDEA key-wrap algorithm is
defined by: defined by:
1. Let the content-encryption key (16 octets) be called CEK 1. Let the content-encryption key (16 octets) be called CEK
2. Compute an 8 octet key checksum value on CEK as described 2. Compute an 8 octet key checksum value on CEK as described in
in [CMS], section 12.6.1, call the result ICV. [CMS], section 12.6.1, call the result ICV.
3. Let CEKICV := CEK || ICV. 3. Let CEKICV := CEK || ICV.
4. Generate 8 octets at random, call the result IV. 4. Generate 8 octets at random, call the result IV.
5. Encrypt CEKICV using IDEA in CBC mode and the key-encryption key. 5. Encrypt CEKICV using IDEA in CBC mode and the key-encryption key.
Use the random value generated in the previous step as the Use the random value generated in the previous step as the
initialization vector (IV). Call the ciphertext TEMP1. initialization vector (IV). Call the ciphertext TEMP1.
6. Let TEMP2 = IV || TEMP1. 6. Let TEMP2 = IV || TEMP1.
7. Reverse the order of the octets in TEMP2. That is, the most 7. Reverse the order of the octets in TEMP2. That is, the most
significant (first) octet is swapped with the least significant significant (first) octet is swapped with the least significant
(last) octet, and so on. Call the result TEMP3. (last) octet, and so on. Call the result TEMP3.
8. Encrypt TEMP3 using IDEA in CBC mode and the key-encryption key. 8. Encrypt TEMP3 using IDEA in CBC mode and the key-encryption key.
Use an initialization vector (IV) of 0x4adda22c79e82105. Use an initialization vector (IV) of 0x4adda22c79e82105. The
The ciphertext is 32 octets long. ciphertext is 32 octets long.
3.2 IDEA Key Unwrap 3.2 IDEA Key Unwrap
The IDEA key-unwrap algorithm decrypts an IDEA content-encryption key The IDEA key-unwrap algorithm decrypts an IDEA content-encryption key
using an IDEA key-encryption key. The IDEA key-unwrap algorithm is using an IDEA key-encryption key. The IDEA key-unwrap algorithm is
defined by: defined by:
1. If the wrapped content-encryption key is not 32 octets, then 1. If the wrapped content-encryption key is not 32 octets, then
error. error.
2. Decrypt the wrapped content-encryption key using IDEA in CBC mode 2. Decrypt the wrapped content-encryption key using IDEA in CBC mode
with the key-encryption key. Use an initialization vector (IV) with the key-encryption key. Use an initialization vector (IV)
of 0x4adda22c79e82105. Call the output TEMP3. of 0x4adda22c79e82105. Call the output TEMP3.
3. Reverse the order of the octets in TEMP3. That is, the most 3. Reverse the order of the octets in TEMP3. That is, the most
significant (first) octet is swapped with the least significant significant (first) octet is swapped with the least significant
(last) octet, and so on. Call the result TEMP2. (last) octet, and so on. Call the result TEMP2.
4. Decompose the TEMP2 into IV and TEMP1. IV is the most significant 4. Decompose the TEMP2 into IV and TEMP1. IV is the most
(first) 8 octets, and TEMP1 is the remaining (last) 24 octets. significant (first) 8 octets, and TEMP1 is the remaining (last)
24 octets.
5. Decrypt TEMP1 using IDEA in CBC mode with the key-encryption key. 5. Decrypt TEMP1 using IDEA in CBC mode with the key-encryption key.
Use the IV value from the previous step as the initialization Use the IV value from the previous step as the initialization
vector. Call the plaintext CEKICV. vector. Call the plaintext CEKICV.
6. Decompose the CEKICV into CEK and ICV. CEK is the most 6. Decompose the CEKICV into CEK and ICV. CEK is the most
significant (first) 16 octets, and ICV is the least significant significant (first) 16 octets, and ICV is the least significant
(last) 8 octets. (last) 8 octets.
7. Compute an 8 octet key checksum value on CEK as described 7. Compute an 8 octet key checksum value on CEK as described in
in [CMS], section 12.6.1. If the computed key checksum value [CMS], section 12.6.1. If the computed key checksum value does
does not match the decrypted key checksum value, ICV, then error. not match the decrypted key checksum value, ICV, then error.
8. Use CEK as the content-encryption key. 8. Use CEK as the content-encryption key.
4. SMIMECapabilities Attribute 4. SMIMECapabilities Attribute
An S/MIME client can announce the set of cryptographic functions An S/MIME client can announce the set of cryptographic functions it
it supports by using the S/MIME capabilities attribute as specified supports by using the S/MIME capabilities attribute as specified in
in [SMIME3]. This attribute provides a partial list of OIDs of [SMIME3]. This attribute provides a partial list of OIDs of
cryptographic functions and must be signed by the client. These OIDs cryptographic functions and must be signed by the client. These OIDs
should be logically separated in functional categories and MUST be should be logically separated in functional categories and MUST be
ordered with respect to their preference. If an S/MIME client is ordered with respect to their preference. If an S/MIME client is
required to support symmetric encryption and key wrapping based on required to support symmetric encryption and key wrapping based on
IDEA, the capabilities attribute MUST contain the above specified IDEA, the capabilities attribute MUST contain the above specified
OIDs in the category of symmetric algorithms and key encipherment OIDs in the category of symmetric algorithms and key encipherment
algorithms. IDEA does not require additional OID parameters since algorithms. IDEA does not require additional OID parameters since it
it has a fixed key length of 128 bits. has a fixed key length of 128 bits.
The SMIMECapability SEQUENCE representing the IDEA symmetric The SMIMECapability SEQUENCE representing the IDEA symmetric
encryption algorithm MUST include the IDEA-CBC OID in the capabilityID encryption algorithm MUST include the IDEA-CBC OID in the
field and the parameters field MUST be absent. The SMIMECapability capabilityID field and the parameters field MUST be absent. The
SEQUENCE for IDEA encryption SHOULD be included in the symmetric SMIMECapability SEQUENCE for IDEA encryption SHOULD be included in
encryption algorithms portion of the SMIMECapabilities list. The the symmetric encryption algorithms portion of the SMIMECapabilities
SMIMECapability SEQUENCE representing IDEA MUST be DER-encoded as list. The SMIMECapability SEQUENCE representing IDEA MUST be DER-
follows: 300D 060B 2B06 0104 0181 3C07 0101 02. encoded as follows: 300D 060B 2B06 0104 0181 3C07 0101 02.
The SMIMECapability SEQUENCE representing the IDEA key wrapping The SMIMECapability SEQUENCE representing the IDEA key wrapping
algorithm MUST include the id-alg-CMSIDEAwrap OID in the capabilityID algorithm MUST include the id-alg-CMSIDEAwrap OID in the capabilityID
field and the parameters field of KeyWrapAlgorithm MUST be absent. field and the parameters field of KeyWrapAlgorithm MUST be absent.
The SMIMECapability SEQUENCE for IDEA key wrapping SHOULD be included The SMIMECapability SEQUENCE for IDEA key wrapping SHOULD be included
in the key encipherment algorithms portion of the SMIMECapabilities in the key encipherment algorithms portion of the SMIMECapabilities
list. The SMIMECapability SEQUENCE representing IDEA key wrapping list. The SMIMECapability SEQUENCE representing IDEA key wrapping
MUST be DER-encoded as follows: 300D 060B 2B06 0104 0181 3C07 0101 MUST be DER-encoded as follows: 300D 060B 2B06 0104 0181 3C07 0101
06. 06.
The ASN.1 notation of the SMIMECapability SEQUENCE representing IDEA
is
SMIMECapability ::= SEQUENCE {
capabilityID OBJECT IDENTIFIER,
parameters ANY DEFINED BY capabilityID OPTIONAL }
where capabilityID is IDEA-CBC (no parameters) for IDEA content
encryption in CBC mode or capabilityID is id-alg-CMSIDEAwrap (no
parameters) for IDEA key wrapping.
5. Activation of IDEA in S/MIME Clients 5. Activation of IDEA in S/MIME Clients
When a sending agent creates an encrypted message, it has to decide When a sending agent creates an encrypted message, it has to decide
which type of encryption algorithm to use. In general the decision which type of encryption algorithm to use. In general the decision
process involves information obtained from the capabilities lists process involves information obtained from the capabilities lists
included in messages received from the recipient, as well as other included in messages received from the recipient, as well as other
information such as private agreements, user preferences, legal information such as private agreements, user preferences, legal
restrictions, etc. If users require IDEA for symmetric encryption, restrictions, etc. If users require IDEA for symmetric encryption,
it must be supported by the S/MIME clients on both the sending and it must be supported by the S/MIME clients on both the sending and
receiving side, and it must be set in the user preferences. receiving side, and it must be set in the user preferences.
A. References A. References
[IDEA] X. Lai, "On the design and security of block ciphers", ETH [IDEA] X. Lai, "On the design and security of block ciphers",
Series in Information Processing, J.L. Massey (editor), vol. 1, ETH Series in Information Processing, J.L. Massey
Hartung-Gorre Verlag Konstanz, Technische Hochschule (Zurich), 1992. (editor), vol. 1, Hartung-Gorre Verlag Konstanz,
A. J. Menezes, P.C. v. Oorschot, S.A. Vanstone, "Handbook of Applied Technische Hochschule (Zurich), 1992. A. J. Menezes,
Cryptography," CRC Press New York, 1997, p. 265. P.C. v. Oorschot, S.A. Vanstone, "Handbook of Applied
B. Schneier, "Applied Cryptography," 2nd ed., John Wiley & Sons Inc. Cryptography," CRC Press New York, 1997, p. 265. B.
New York, 1996, pp. 319-325. Schneier, "Applied Cryptography," 2nd ed., John Wiley &
IPR: see the "IETF Page of Intellectual Property Rights Notices", Sons Inc. New York, 1996, pp. 319-325. IPR: see the
http://www.ietf.org/ipr.html "IETF Page of Intellectual Property Rights Notices",
http://www.ietf.org/ipr.html
[SMIME2] "S/MIME Version 2 Message Specification", RFC 2311, and [SMIME2] Dusse, S., Hoffman, P., Ramsdell, B., Lundblade, l. and
"S/MIME Version 2 Certificate Handling", RFC 2312. L. Repka, "S/MIME Version 2 Message Specification", RFC
2311, March 1998.
[SMIME3] "S/MIME Version 3 Certificate Handling", RFC 2632, and [SMIME2] Dusse, S., Hoffman, P., Ramsdell, B. and J. Weinstein,
"S/MIME Version 3 Message Specification", RFC 2633. "S/MIME Version 2 Certificate Handling", RFC 2312, March
1998.
[MUSTSHOULD] "Key words for use in RFCs to Indicate Requirement [SMIME3] Dusse, S., Hoffman, P., Ramsdell, B. and J. Weinstein,
Levels", RFC 2119. "S/MIME Version 3 Certificate Handling", RFC 2632, March
1998.
[CMS] "Cryptographic Message Syntax", RFC 2630. [SMIME3] Ramsdell, B., "S/MIME Version 3 Message Specification",
RFC 2633, June 1999.
[PKCS7] "PKCS #7: Cryptographic Message Syntax Version 1.5", [MUSTSHOULD] Bradner, S.,"Key words for use in RFCs to Indicate
RFC 2315. Requirement Levels", BCP 14, RFC 2119, March 1997.
[CMS] Housley, R., "Cryptographic Message Syntax", RFC 2630,
June 1999.
[PKCS7] Kaliski, B., "PKCS #7: Cryptographic Message Syntax
Version 1.5", RFC 2315, March 1998.
B. Comments on IDEA Security and Standards B. Comments on IDEA Security and Standards
The IDEA algorithm was developed in a joint project involving the The IDEA algorithm was developed in a joint project involving the
Swiss Federal Institute of Technology in Zurich (Dr. X. Lai and Swiss Federal Institute of Technology in Zurich (Dr. X. Lai and Prof.
Prof. J.L. Massey) and Ascom Ltd. The aim of the project was to J.L. Massey) and Ascom Ltd. The aim of the project was to develop a
develop a strong encryption algorithm that could replace the DES strong encryption algorithm that could replace the DES algorithm.
algorithm.
IDEA uses 128-bit secret keys and encrypts one 64-bit block at a IDEA uses 128-bit secret keys and encrypts one 64-bit block at a time
time [IDEA]. It was particularly strengthened to protect against [IDEA]. It was particularly strengthened to protect against
differential cryptoanalysis attacks. For the full 8-round IDEA differential cryptoanalysis attacks. For the full 8-round IDEA there
there is no attack known which is better than exhaustive search is no attack known which is better than exhaustive search on the
on the total 128-bit key space. total 128-bit key space.
IDEA permits the implementation of standard Electronic Data IDEA permits the implementation of standard Electronic Data
Interchange applications. It has been entered in the ISO/IEC register Interchange applications. It has been entered in the ISO/IEC
for encryption algorithms and incorporated in the "SECURITY GUIDE register for encryption algorithms and incorporated in the "SECURITY
LINES" code list by the UNI/EDIFACT "SECURITY JOINT WORKING GROUP". GUIDE LINES" code list by the UNI/EDIFACT "SECURITY JOINT WORKING
GROUP".
C. Intellectual Property Rights Notice C. Intellectual Property Rights Notice
Ascom Ltd. holds the patent to IDEA. In accordance with the Ascom Ltd. holds the patent to IDEA. In accordance with the
intellectual property rights procedures of the IETF standards intellectual property rights procedures of the IETF standards
process, Ascom offers a non-exclusive license under reasonable and process, Ascom offers a non-exclusive license under reasonable and
non-discriminatory terms and conditions. non-discriminatory terms and conditions.
IDEA(TM) is protected by international copyright law and in addition IDEA(TM) is protected by international copyright law and in addition
has been patented in several countries. Because Ascom wants to make has been patented in several countries. Because Ascom wants to make
this highly secure algorithm widely available, the non-commercial use this highly secure algorithm widely available, the non-commercial use
of this algorithm is free. of this algorithm is free.
Any party wishing to know more about IDEA or to request a license Any party wishing to know more about IDEA or to request a license
should visit the web sites should visit the web sites <http://www.media-crypt.com/>,
<http://www.media-crypt.com/>, <http://www.it-sec.com/> <http://www.it-sec.com/> or send an e-mail to info@media-crypt.com or
or send an e-mail to Idea@it-sec.com.
info@media-crypt.com or Idea@it-sec.com.
D. Acknowledgements D. Acknowledgements
We would like to thank Russ Housley, Jim Schaad and Francois Zeller We would like to thank Russ Housley, Jim Schaad and Francois Zeller
for their contributions to this document. for their contributions to this document.
E. Authors' Address E. Authors' Addresses
Stephan Teiwes
iT_Security AG (Ltd.) iT_Security AG (Ltd.)
Badenerstrasse 530 Badenerstrasse 530
CH-8048 Zurich, Switzerland
Phone: +41 1 404 8200
Fax : +41 1 404 8201
EMail: stephan.teiwes@it-sec.com
Peter Hartmann
iT_Security AG (Ltd.)
Badenerstrasse 530
CH-8048 Zurich, Switzerland CH-8048 Zurich, Switzerland
Phone: +41 1 236 9900 Phone: +41 1 404 8200
Fax : +41 1 236 9990 Fax : +41 1 404 8201
Email: {stephan.teiwes,peter.hartmann,diego.kuenzi}@it-sec.com EMail: peter.hartmann@it-sec.com
F. Full Copyright Statement Diego Kuenzi
724 Solutions Inc.
Bahnhofstrasse 16
CH-5600 Lenzburg, Switzerland
Phone: +41 62 888 3070
Fax: +41 62 888 3071
EMail: dkuenzi@724.com
F. Full Copyright Statement
Copyright (C) The Internet Society (2001). All Rights Reserved.
Copyright (C) The Internet Society (date). All Rights Reserved.
This document and translations of it may be copied and furnished to This document and translations of it may be copied and furnished to
others, and derivative works that comment on or otherwise explain it others, and derivative works that comment on or otherwise explain it
or assist in its implementation may be prepared, copied, published or assist in its implementation may be prepared, copied, published
and distributed, in whole or in part, without restriction of any and distributed, in whole or in part, without restriction of any
kind, provided that the above copyright notice and this paragraph kind, provided that the above copyright notice and this paragraph are
are included on all such copies and derivative works. However, this included on all such copies and derivative works. However, this
document itself may not be modified in any way, such as by removing document itself may not be modified in any way, such as by removing
the copyright notice or references to the Internet Society or other the copyright notice or references to the Internet Society or other
Internet organizations, except as needed for the purpose of Internet organizations, except as needed for the purpose of
developing Internet standards in which case the procedures for developing Internet standards in which case the procedures for
copyrights defined in the Internet Standards process shall be copyrights defined in the Internet Standards process must be
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FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING
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Acknowledgement
Funding for the RFC Editor function is currently provided by the
Internet Society.
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