 1/draftietfjosejsonwebalgorithms01.txt 20120528 12:16:14.729788259 +0200
+++ 2/draftietfjosejsonwebalgorithms02.txt 20120528 12:16:14.781758397 +0200
@@ 1,18 +1,18 @@
JOSE Working Group M. Jones
InternetDraft Microsoft
Intended status: Standards Track March 12, 2012
Expires: September 13, 2012
+Intended status: Standards Track May 12, 2012
+Expires: November 13, 2012
JSON Web Algorithms (JWA)
 draftietfjosejsonwebalgorithms01
+ draftietfjosejsonwebalgorithms02
Abstract
The JSON Web Algorithms (JWA) specification enumerates cryptographic
algorithms and identifiers to be used with the JSON Web Signature
(JWS) and JSON Web Encryption (JWE) specifications.
Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
@@ 27,65 +27,98 @@
InternetDrafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as InternetDrafts. The list of current Internet
Drafts is at http://datatracker.ietf.org/drafts/current/.
InternetDrafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use InternetDrafts as reference
material or to cite them other than as "work in progress."
 This InternetDraft will expire on September 13, 2012.
+ This InternetDraft will expire on November 13, 2012.
Copyright Notice
Copyright (c) 2012 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(http://trustee.ietf.org/licenseinfo) in effect on the date of
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
 3. Cryptographic Algorithms for JWS . . . . . . . . . . . . . . . 3
 3.1. Creating a JWS with HMAC SHA256, HMAC SHA384, or
 HMAC SHA512 . . . . . . . . . . . . . . . . . . . . . . . 4
 3.2. Creating a JWS with RSA SHA256, RSA SHA384, or RSA
 SHA512 . . . . . . . . . . . . . . . . . . . . . . . . . 5
 3.3. Creating a JWS with ECDSA P256 SHA256, ECDSA P384
 SHA384, or ECDSA P521 SHA512 . . . . . . . . . . . . . 6
 3.4. Creating a Plaintext JWS . . . . . . . . . . . . . . . . . 7
 3.5. Additional Digital Signature/HMAC Algorithms . . . . . . . 7
 4. Cryptographic Algorithms for JWE . . . . . . . . . . . . . . . 8
 4.1. Encrypting a JWE with TBD . . . . . . . . . . . . . . . . 9
 4.2. Additional Encryption Algorithms . . . . . . . . . . . . . 9
 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 10
 6. Security Considerations . . . . . . . . . . . . . . . . . . . 10
 7. Open Issues and Things To Be Done (TBD) . . . . . . . . . . . 10
 8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 11
 8.1. Normative References . . . . . . . . . . . . . . . . . . . 11
 8.2. Informative References . . . . . . . . . . . . . . . . . . 12
 Appendix A. Digital Signature/HMAC Algorithm Identifier
 CrossReference . . . . . . . . . . . . . . . . . . . 13
 Appendix B. Encryption Algorithm Identifier CrossReference . . . 15
 Appendix C. Acknowledgements . . . . . . . . . . . . . . . . . . 19
 Appendix D. Document History . . . . . . . . . . . . . . . . . . 19
 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 19
+ 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4
+ 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4
+ 3. Cryptographic Algorithms for JWS . . . . . . . . . . . . . . . 4
+ 3.1. "alg" (Algorithm) Header Parameter Values for JWS . . . . 4
+ 3.2. MAC with HMAC SHA256, HMAC SHA384, or HMAC SHA512 . . . 5
+ 3.3. Digital Signature with RSA SHA256, RSA SHA384, or
+ RSA SHA512 . . . . . . . . . . . . . . . . . . . . . . . 6
+ 3.4. Digital Signature with ECDSA P256 SHA256, ECDSA
+ P384 SHA384, or ECDSA P521 SHA512 . . . . . . . . . . 7
+ 3.5. Creating a Plaintext JWS . . . . . . . . . . . . . . . . . 9
+ 3.6. Additional Digital Signature/MAC Algorithms and
+ Parameters . . . . . . . . . . . . . . . . . . . . . . . . 9
+ 4. Cryptographic Algorithms for JWE . . . . . . . . . . . . . . . 9
+ 4.1. "alg" (Algorithm) Header Parameter Values for JWE . . . . 9
+ 4.2. "enc" (Encryption Method) Header Parameter Values for
+ JWE . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
+ 4.3. "int" (Integrity Algorithm) Header Parameter Values
+ for JWE . . . . . . . . . . . . . . . . . . . . . . . . . 11
+ 4.4. Key Encryption with RSA using RSAPKCS11.5 Padding . . . 11
+ 4.5. Key Encryption with RSA using Optimal Asymmetric
+ Encryption Padding (OAEP) . . . . . . . . . . . . . . . . 11
+ 4.6. Key Agreement with Elliptic Curve DiffieHellman
+ Ephemeral Static (ECDHES) . . . . . . . . . . . . . . . . 12
+ 4.7. Key Encryption with AES Key Wrap . . . . . . . . . . . . . 12
+ 4.8. Plaintext Encryption with AES Cipher Block Chaining
+ (CBC) Mode . . . . . . . . . . . . . . . . . . . . . . . . 12
+ 4.9. Plaintext Encryption with AES Galois/Counter Mode (GCM) . 12
+ 4.10. Integrity Calculation with HMAC SHA256, HMAC SHA384,
+ or HMAC SHA512 . . . . . . . . . . . . . . . . . . . . . 13
+ 4.11. Additional Encryption Algorithms and Parameters . . . . . 13
+ 5. Cryptographic Algorithms for JWK . . . . . . . . . . . . . . . 13
+ 5.1. "alg" (Algorithm Family) Parameter Values for JWK . . . . 14
+ 5.2. JWK Parameters for Elliptic Curve Keys . . . . . . . . . . 14
+ 5.2.1. "crv" (Curve) Parameter . . . . . . . . . . . . . . . 14
+ 5.2.2. "x" (X Coordinate) Parameter . . . . . . . . . . . . . 14
+ 5.2.3. "y" (Y Coordinate) Parameter . . . . . . . . . . . . . 14
+ 5.3. JWK Parameters for RSA Keys . . . . . . . . . . . . . . . 14
+ 5.3.1. "mod" (Modulus) Parameter . . . . . . . . . . . . . . 15
+ 5.3.2. "exp" (Exponent) Parameter . . . . . . . . . . . . . . 15
+ 5.4. Additional Key Algorithm Families and Parameters . . . . . 15
+
+ 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 15
+ 6.1. JSON Web Signature and Encryption Header Parameters
+ Registry . . . . . . . . . . . . . . . . . . . . . . . . . 15
+ 6.2. JSON Web Signature and Encryption Algorithms Registry . . 15
+ 6.3. JSON Web Signature and Encryption "typ" Values Registry . 16
+ 6.4. JSON Web Key Parameters Registry . . . . . . . . . . . . . 16
+ 6.5. JSON Web Key Algorithm Families Registry . . . . . . . . . 16
+ 7. Security Considerations . . . . . . . . . . . . . . . . . . . 16
+ 8. Open Issues and Things To Be Done (TBD) . . . . . . . . . . . 17
+ 9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 17
+ 9.1. Normative References . . . . . . . . . . . . . . . . . . . 17
+ 9.2. Informative References . . . . . . . . . . . . . . . . . . 18
+ Appendix A. Digital Signature/MAC Algorithm Identifier
+ CrossReference . . . . . . . . . . . . . . . . . . . 19
+ Appendix B. Encryption Algorithm Identifier CrossReference . . . 21
+ Appendix C. Acknowledgements . . . . . . . . . . . . . . . . . . 25
+ Appendix D. Document History . . . . . . . . . . . . . . . . . . 25
+ Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 26
1. Introduction
The JSON Web Algorithms (JWA) specification enumerates cryptographic
algorithms and identifiers to be used with the JSON Web Signature
(JWS) [JWS] and JSON Web Encryption (JWE) [JWE] specifications.
Enumerating the algorithms and identifiers for them in this
specification, rather than in the JWS and JWE specifications, is
intended to allow them to remain unchanged in the face of changes in
the set of required, recommended, optional, and deprecated algorithms
@@ 94,176 +127,192 @@
families.
2. Terminology
This specification uses the terminology defined by the JSON Web
Signature (JWS) [JWS] and JSON Web Encryption (JWE) [JWE]
specifications.
3. Cryptographic Algorithms for JWS
 JWS uses cryptographic algorithms to sign the contents of the JWS
 Header and the JWS Payload. The use of the following algorithms for
 producing JWSs is defined in this section.
+ JWS uses cryptographic algorithms to digitally sign or MAC the
+ contents of the JWS Header and the JWS Payload. The use of the
+ following algorithms for producing JWSs is defined in this section.
 The table below Table 1 is the set of "alg" (algorithm) header
 parameter values defined by this specification for use with JWS, each
 of which is explained in more detail in the following sections:
+3.1. "alg" (Algorithm) Header Parameter Values for JWS
+
+ The table below is the set of "alg" (algorithm) header parameter
+ values defined by this specification for use with JWS, each of which
+ is explained in more detail in the following sections:
+++
  Alg Parameter  Algorithm 
+  alg Parameter  Digital Signature or MAC Algorithm 
 Value  
+++
 HS256  HMAC using SHA256 hash algorithm 
 HS384  HMAC using SHA384 hash algorithm 
 HS512  HMAC using SHA512 hash algorithm 
 RS256  RSA using SHA256 hash algorithm 
 RS384  RSA using SHA384 hash algorithm 
 RS512  RSA using SHA512 hash algorithm 
 ES256  ECDSA using P256 curve and SHA256 hash 
  algorithm 
 ES384  ECDSA using P384 curve and SHA384 hash 
  algorithm 
 ES512  ECDSA using P521 curve and SHA512 hash 
  algorithm 
  none  No digital signature or HMAC value included 
+  none  No digital signature or MAC value included 
+++
 Table 1: JWS Defined "alg" Parameter Values

See Appendix A for a table crossreferencing the digital signature
 and HMAC "alg" (algorithm) values used in this specification with the
+ and MAC "alg" (algorithm) values used in this specification with the
equivalent identifiers used by other standards and software packages.
Of these algorithms, only HMAC SHA256 and "none" MUST be implemented
by conforming JWS implementations. It is RECOMMENDED that
implementations also support the RSA SHA256 and ECDSA P256 SHA256
algorithms. Support for other algorithms and key sizes is OPTIONAL.
3.1. Creating a JWS with HMAC SHA256, HMAC SHA384, or HMAC SHA512
+3.2. MAC with HMAC SHA256, HMAC SHA384, or HMAC SHA512
 Hash based Message Authentication Codes (HMACs) enable one to use a
+ Hashbased Message Authentication Codes (HMACs) enable one to use a
secret plus a cryptographic hash function to generate a Message
Authentication Code (MAC). This can be used to demonstrate that the
MAC matches the hashed content, in this case the JWS Secured Input,
which therefore demonstrates that whoever generated the MAC was in
possession of the secret. The means of exchanging the shared key is
outside the scope of this specification.
The algorithm for implementing and validating HMACs is provided in
RFC 2104 [RFC2104]. This section defines the use of the HMAC SHA
256, HMAC SHA384, and HMAC SHA512 cryptographic hash functions as
defined in FIPS 1803 [FIPS.1803]. The "alg" (algorithm) header
parameter values "HS256", "HS384", and "HS512" are used in the JWS
Header to indicate that the Encoded JWS Signature contains a
base64url encoded HMAC value using the respective hash function.
+ A key of the same size as the hash output (for instance, 256 bits for
+ "HS256") or larger MUST be used with this algorithm.
+
The HMAC SHA256 MAC is generated as follows:
 1. Apply the HMAC SHA256 algorithm to the UTF8 representation of
 the JWS Secured Input using the shared key to produce an HMAC
+ 1. Apply the HMAC SHA256 algorithm to the bytes of the UTF8
+ representation of the JWS Secured Input (which is the same as the
+ ASCII representation) using the shared key to produce an HMAC
value.
2. Base64url encode the resulting HMAC value.
The output is the Encoded JWS Signature for that JWS.
The HMAC SHA256 MAC for a JWS is validated as follows:
 1. Apply the HMAC SHA256 algorithm to the UTF8 representation of
 the JWS Secured Input of the JWS using the shared key.
+ 1. Apply the HMAC SHA256 algorithm to the bytes of the UTF8
+ representation of the JWS Secured Input (which is the same as the
+ ASCII representation) of the JWS using the shared key.
2. Base64url encode the resulting HMAC value.
3. If the Encoded JWS Signature and the base64url encoded HMAC value
exactly match, then one has confirmation that the shared key was
used to generate the HMAC on the JWS and that the contents of the
JWS have not be tampered with.
4. If the validation fails, the JWS MUST be rejected.
Alternatively, the Encoded JWS Signature MAY be base64url decoded to
produce the JWS Signature and this value can be compared with the
computed HMAC value, as this comparison produces the same result as
comparing the encoded values.
Securing content with the HMAC SHA384 and HMAC SHA512 algorithms is
performed identically to the procedure for HMAC SHA256  just with
 correspondingly longer minimum key sizes and result values.
+ correspondingly larger minimum key sizes and result values.
3.2. Creating a JWS with RSA SHA256, RSA SHA384, or RSA SHA512
+3.3. Digital Signature with RSA SHA256, RSA SHA384, or RSA SHA512
This section defines the use of the RSASSAPKCS1v1_5 digital
signature algorithm as defined in RFC 3447 [RFC3447], Section 8.2
(commonly known as PKCS#1), using SHA256, SHA384, or SHA512 as the
hash function. The RSASSAPKCS1v1_5 algorithm is described in FIPS
1863 [FIPS.1863], Section 5.5, and the SHA256, SHA384, and SHA
512 cryptographic hash functions are defined in FIPS 1803
[FIPS.1803]. The "alg" (algorithm) header parameter values "RS256",
"RS384", and "RS512" are used in the JWS Header to indicate that the
Encoded JWS Signature contains a base64url encoded RSA digital
signature using the respective hash function.
 A 2048bit or longer key length MUST be used with this algorithm.
+ A key of size 2048 bits or larger MUST be used with these algorithms.
+
+ Note that while Section 8 of RFC 3447 [RFC3447] explicitly calls for
+ people not to adopt RSASSAPKCS1 for new applications and instead
+ requests that people transition to RSASSAPSS, for interoperability
+ reasons, this specification does use RSASSAPKCS1 because it commonly
+ implemented.
The RSA SHA256 digital signature is generated as follows:
 1. Generate a digital signature of the UTF8 representation of the
 JWS Secured Input using RSASSAPKCS1V1_5SIGN and the SHA256
 hash function with the desired private key. The output will be a
 byte array.
+ 1. Generate a digital signature of the bytes of the UTF8
+ representation of the JWS Secured Input (which is the same as the
+ ASCII representation) using RSASSAPKCS1V1_5SIGN and the SHA
+ 256 hash function with the desired private key. The output will
+ be a byte array.
2. Base64url encode the resulting byte array.
The output is the Encoded JWS Signature for that JWS.
The RSA SHA256 digital signature for a JWS is validated as follows:
1. Take the Encoded JWS Signature and base64url decode it into a
byte array. If decoding fails, the JWS MUST be rejected.
 2. Submit the UTF8 representation of the JWS Secured Input and the
+ 2. Submit the bytes of the UTF8 representation of the JWS Secured
+ Input (which is the same as the ASCII representation) and the
public key corresponding to the private key used by the signer to
the RSASSAPKCS1V1_5VERIFY algorithm using SHA256 as the hash
function.
3. If the validation fails, the JWS MUST be rejected.
Signing with the RSA SHA384 and RSA SHA512 algorithms is performed
identically to the procedure for RSA SHA256  just with
 correspondingly longer minimum key sizes and result values.
+ correspondingly larger result values.
3.3. Creating a JWS with ECDSA P256 SHA256, ECDSA P384 SHA384, or
 ECDSA P521 SHA512
+3.4. Digital Signature with ECDSA P256 SHA256, ECDSA P384 SHA384,
+ or ECDSA P521 SHA512
The Elliptic Curve Digital Signature Algorithm (ECDSA) is defined by
FIPS 1863 [FIPS.1863]. ECDSA provides for the use of Elliptic
Curve cryptography, which is able to provide equivalent security to
 RSA cryptography but using shorter key lengths and with greater
+ RSA cryptography but using shorter key sizes and with greater
processing speed. This means that ECDSA digital signatures will be
substantially smaller in terms of length than equivalently strong RSA
digital signatures.
This specification defines the use of ECDSA with the P256 curve and
the SHA256 cryptographic hash function, ECDSA with the P384 curve
and the SHA384 hash function, and ECDSA with the P521 curve and the
SHA512 hash function. The P256, P384, and P521 curves are also
defined in FIPS 1863. The "alg" (algorithm) header parameter values
"ES256", "ES384", and "ES512" are used in the JWS Header to indicate
that the Encoded JWS Signature contains a base64url encoded ECDSA
P256 SHA256, ECDSA P384 SHA384, or ECDSA P521 SHA512 digital
signature, respectively.
+ A key of size 160 bits or larger MUST be used with these algorithms.
+
The ECDSA P256 SHA256 digital signature is generated as follows:
 1. Generate a digital signature of the UTF8 representation of the
 JWS Secured Input using ECDSA P256 SHA256 with the desired
+ 1. Generate a digital signature of the bytes of the UTF8
+ representation of the JWS Secured Input (which is the same as the
+ ASCII representation) using ECDSA P256 SHA256 with the desired
private key. The output will be the EC point (R, S), where R and
S are unsigned integers.
2. Turn R and S into byte arrays in big endian order. Each array
will be 32 bytes long.
3. Concatenate the two byte arrays in the order R and then S.
4. Base64url encode the resulting 64 byte array.
@@ 271,259 +320,475 @@
The ECDSA P256 SHA256 digital signature for a JWS is validated as
follows:
1. Take the Encoded JWS Signature and base64url decode it into a
byte array. If decoding fails, the JWS MUST be rejected.
2. The output of the base64url decoding MUST be a 64 byte array.
3. Split the 64 byte array into two 32 byte arrays. The first array
 will be R and the second S. Remember that the byte arrays are in
 big endian byte order; please check the ECDSA validator in use to
 see what byte order it requires.
+ will be R and the second S (with both being in big endian byte
+ order).
 4. Submit the UTF8 representation of the JWS Secured Input, R, S
 and the public key (x, y) to the ECDSA P256 SHA256 validator.
+ 4. Submit the bytes of the UTF8 representation of the JWS Secured
+ Input (which is the same as the ASCII representation), R, S and
+ the public key (x, y) to the ECDSA P256 SHA256 validator.
5. If the validation fails, the JWS MUST be rejected.
The ECDSA validator will then determine if the digital signature is
valid, given the inputs. Note that ECDSA digital signature contains
a value referred to as K, which is a random number generated for each
digital signature instance. This means that two ECDSA digital
signatures using exactly the same input parameters will output
different signature values because their K values will be different.
The consequence of this is that one must validate an ECDSA digital
signature by submitting the previously specified inputs to an ECDSA
validator.
Signing with the ECDSA P384 SHA384 and ECDSA P521 SHA512
algorithms is performed identically to the procedure for ECDSA P256
 SHA256  just with correspondingly longer minimum key sizes and
 result values.
+ SHA256  just with correspondingly larger result values.
3.4. Creating a Plaintext JWS
+3.5. Creating a Plaintext JWS
To support use cases where the content is secured by a means other
 than a digital signature or HMAC value, JWSs MAY also be created
+ than a digital signature or MAC value, JWSs MAY also be created
without them. These are called "Plaintext JWSs". Plaintext JWSs
MUST use the "alg" value "none", and are formatted identically to
other JWSs, but with an empty JWS Signature value.
3.5. Additional Digital Signature/HMAC Algorithms
+3.6. Additional Digital Signature/MAC Algorithms and Parameters
Additional algorithms MAY be used to protect JWSs with corresponding
"alg" (algorithm) header parameter values being defined to refer to
them. New "alg" header parameter values SHOULD either be defined in
 the IANA JSON Web Signature Algorithms registry or be a URI that
 contains a collision resistant namespace. In particular, it is
 permissible to use the algorithm identifiers defined in XML DSIG
 [RFC3275] and related specifications as "alg" values.
+ the IANA JSON Web Signature and Encryption Algorithms registry
+ Section 6.2 or be a URI that contains a collision resistant
+ namespace. In particular, it is permissible to use the algorithm
+ identifiers defined in XML DSIG [RFC3275], XML DSIG 2.0
+ [W3C.CRxmldsigcore220120124], and related specifications as "alg"
+ values.
+
+ As indicated by the common registry, JWSs and JWEs share a common
+ "alg" value space. The values used by the two specifications MUST be
+ distinct, as the "alg" value MAY be used to determine whether the
+ object is a JWS or JWE.
+
+ Likewise, additional reserved header parameter names MAY be defined
+ via the IANA JSON Web Signature and Encryption Header Parameters
+ registry Section 6.1. 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. Cryptographic Algorithms for JWE
 JWE uses cryptographic algorithms to encrypt the Content Encryption
 Key (CEK) and the Plaintext. This section specifies a set of
 specific algorithms for these purposes.
+ JWE uses cryptographic algorithms to encrypt the Content Master Key
+ (CMK) and the Plaintext. This section specifies a set of specific
+ algorithms for these purposes.
 The table below Table 2 is the set of "alg" (algorithm) header
 parameter values that are defined by this specification for use with
 JWE. These algorithms are used to encrypt the CEK, which produces
 the JWE Encrypted Key.
+4.1. "alg" (Algorithm) Header Parameter Values for JWE
+
+ The table below is the set of "alg" (algorithm) header parameter
+ values that are defined by this specification for use with JWE.
+ These algorithms are used to encrypt the CMK, producing the JWE
+ Encrypted Key, or to use key agreement to agree upon the CMK.
+++
  alg  Encryption Algorithm 
+  alg  Key Encryption or Agreement Algorithm 
 Parameter  
 Value  
+++
 RSA1_5  RSA using RSAPKCS11.5 padding, as defined in RFC 
  3447 [RFC3447] 
 RSAOAEP  RSA using Optimal Asymmetric Encryption Padding 
  (OAEP), as defined in RFC 3447 [RFC3447] 
 ECDHES  Elliptic Curve DiffieHellman Ephemeral Static, as 
  defined in RFC 6090 [RFC6090], and using the Concat 
   KDF, as defined in [NIST80056A], where the Digest 
   Method is SHA256 and all OtherInfo parameters are 
   the empty bit string 
+   KDF, as defined in Section 5.8.1 of [NIST.80056A], 
+   where the Digest Method is SHA256 and all OtherInfo 
+   parameters are the empty bit string 
 A128KW  Advanced Encryption Standard (AES) Key Wrap Algorithm 
  using 128 bit keys, as defined in RFC 3394 [RFC3394] 
 A256KW  Advanced Encryption Standard (AES) Key Wrap Algorithm 
  using 256 bit keys, as defined in RFC 3394 [RFC3394] 
  A512KW  Advanced Encryption Standard (AES) Key Wrap Algorithm 
   using 512 bit keys, as defined in RFC 3394 [RFC3394] 
  A128GCM  Advanced Encryption Standard (AES) using 128 bit keys 
   in Galois/Counter Mode, as defined in [FIPS197] and 
   [NIST80038D] 
  A256GCM  Advanced Encryption Standard (AES) using 256 bit keys 
   in Galois/Counter Mode, as defined in [FIPS197] and 
   [NIST80038D] 
+++
 Table 2: JWE Defined "alg" Parameter Values
+4.2. "enc" (Encryption Method) Header Parameter Values for JWE
 The table below Table 3 is the set of "enc" (encryption method)
 header parameter values that are defined by this specification for
 use with JWE. These algorithms are used to encrypt the Plaintext,
 which produces the Ciphertext.
+ The table below is the set of "enc" (encryption method) header
+ parameter values that are defined by this specification for use with
+ JWE. These algorithms are used to encrypt the Plaintext, which
+ produces the Ciphertext.
+++
  enc  Symmetric Encryption Algorithm 
+  enc  Block Encryption Algorithm 
 Parameter  
 Value  
+++
 A128CBC  Advanced Encryption Standard (AES) using 128 bit keys 
   in Cipher Block Chaining mode, as defined in 
   [FIPS197] and [NIST80038A] 
+   in Cipher Block Chaining (CBC) mode using PKCS #5 
+   padding, as defined in [FIPS.197] and [NIST.80038A] 
 A256CBC  Advanced Encryption Standard (AES) using 256 bit keys 
   in Cipher Block Chaining mode, as defined in 
   [FIPS197] and [NIST80038A] 
+   in Cipher Block Chaining (CBC) mode using PKCS #5 
+   padding, as defined in [FIPS.197] and [NIST.80038A] 
 A128GCM  Advanced Encryption Standard (AES) using 128 bit keys 
   in Galois/Counter Mode, as defined in [FIPS197] and 
   [NIST80038D] 
+   in Galois/Counter Mode (GCM), as defined in 
+   [FIPS.197] and [NIST.80038D] 
 A256GCM  Advanced Encryption Standard (AES) using 256 bit keys 
   in Galois/Counter Mode, as defined in [FIPS197] and 
   [NIST80038D] 
+   in Galois/Counter Mode (GCM), as defined in 
+   [FIPS.197] and [NIST.80038D] 
+++
 Table 3: JWE Defined "enc" Parameter Values

See Appendix B for a table crossreferencing the encryption "alg"
(algorithm) and "enc" (encryption method) values used in this
specification with the equivalent identifiers used by other standards
and software packages.
 Of these algorithms, only RSAPKCS11.5 with 2048 bit keys, AES128
 CBC, and AES256CBC MUST be implemented by conforming JWE
 implementations. It is RECOMMENDED that implementations also support
 ECDHES with 256 bit keys, AES128GCM, and AES256GCM. Support for
 other algorithms and key sizes is OPTIONAL.
+ Of these "alg" and "enc" algorithms, only RSAPKCS11.5 with 2048 bit
+ keys, AES128KW, AES256KW, AES128CBC, and AES256CBC MUST be
+ implemented by conforming JWE implementations. It is RECOMMENDED
+ that implementations also support ECDHES with 256 bit keys, AES128
+ GCM, and AES256GCM. Support for other algorithms and key sizes is
+ OPTIONAL.
4.1. Encrypting a JWE with TBD
+4.3. "int" (Integrity Algorithm) Header Parameter Values for JWE
 TBD: Descriptions of the particulars of using each specified
 encryption algorithm go here.
+ The table below is the set of "int" (integrity algorithm) header
+ parameter values defined by this specification for use with JWE.
+ Note that these are the HMAC SHA subset of the "alg" (algorithm)
+ header parameter values defined for use with JWS Section 3.1. />
4.2. Additional Encryption Algorithms
+ +++
+  int Parameter Value  Algorithm 
+ +++
+  HS256  HMAC using SHA256 hash algorithm 
+  HS384  HMAC using SHA384 hash algorithm 
+  HS512  HMAC using SHA512 hash algorithm 
+ +++
+
+ Of these "int" algorithms, only HMAC SHA256 MUST be implemented by
+ conforming JWE implementations. It is RECOMMENDED that
+ implementations also support the RSA SHA256 and ECDSA P256 SHA256
+ algorithms.
+
+4.4. Key Encryption with RSA using RSAPKCS11.5 Padding
+
+ This section defines the specifics of encrypting a JWE CMK with RSA
+ using RSAPKCS11.5 padding, as defined in RFC 3447 [RFC3447]. The
+ "alg" header parameter value "RSA1_5" is used in this case.
+
+ A key of size 2048 bits or larger MUST be used with this algorithm.
+
+4.5. Key Encryption with RSA using Optimal Asymmetric Encryption
+ Padding (OAEP)
+
+ This section defines the specifics of encrypting a JWE CMK with RSA
+ using Optimal Asymmetric Encryption Padding (OAEP), as defined in RFC
+ 3447 [RFC3447]. The "alg" header parameter value "RSAOAEP" is used
+ in this case.
+
+ A key of size 2048 bits or larger MUST be used with this algorithm.
+
+4.6. Key Agreement with Elliptic Curve DiffieHellman Ephemeral Static
+ (ECDHES)
+
+ This section defines the specifics of agreeing upon a JWE CMK with
+ Elliptic Curve DiffieHellman Ephemeral Static, as defined in RFC
+ 6090 [RFC6090], and using the Concat KDF, as defined in Section 5.8.1
+ of [NIST.80056A], where the Digest Method is SHA256 and all
+ OtherInfo parameters are the empty bit string. The "alg" header
+ parameter value "ECDHES" is used in this case.
+
+ A key of size 160 bits or larger MUST be used for the Elliptic Curve
+ keys used with this algorithm. The output of the Concat KDF MUST be
+ a key of the same length as that used by the "enc" algorithm.
+
+ An "epk" (ephemeral public key) value MUST only be used for a single
+ key agreement transaction.
+
+4.7. Key Encryption with AES Key Wrap
+
+ This section defines the specifics of encrypting a JWE CMK with the
+ Advanced Encryption Standard (AES) Key Wrap Algorithm using 128 or
+ 256 bit keys, as defined in RFC 3394 [RFC3394]. The "alg" header
+ parameter values "A128KW" or "A256KW" are used in this case.
+
+4.8. Plaintext Encryption with AES Cipher Block Chaining (CBC) Mode
+
+ This section defines the specifics of encrypting the JWE Plaintext
+ with Advanced Encryption Standard (AES) in Cipher Block Chaining
+ (CBC) mode using PKCS #5 padding using 128 or 256 bit keys, as
+ defined in [FIPS.197] and [NIST.80038A]. The "enc" header parameter
+ values "A128CBC" or "A256CBC" are used in this case.
+
+ Use of an Initialization Vector (IV) of size 128 bits is RECOMMENDED
+ with this algorithm.
+
+4.9. Plaintext Encryption with AES Galois/Counter Mode (GCM)
+
+ This section defines the specifics of encrypting the JWE Plaintext
+ with Advanced Encryption Standard (AES) in Galois/Counter Mode (GCM)
+ using 128 or 256 bit keys, as defined in [FIPS.197] and
+ [NIST.80038D]. The "enc" header parameter values "A128GCM" or
+ "A256GCM" are used in this case.
+
+ Use of an Initialization Vector (IV) of size 96 bits is REQUIRED with
+ this algorithm.
+
+ The "additional authenticated data" parameter value for the
+ encryption is the concatenation of the Encoded JWE Header, a period
+ ('.') character, and the Encoded JWE Encrypted Key.
+
+ The requested size of the "authentication tag" output MUST be the
+ same as the key size (for instance, 128 bits for "A128GCM").
+
+ As GCM is an AEAD algorithm, the JWE Integrity Value is set to be the
+ "authentication tag" value produced by the encryption.
+
+4.10. Integrity Calculation with HMAC SHA256, HMAC SHA384, or HMAC
+ SHA512
+
+ This section defines the specifics of computing a JWE Integrity Value
+ with HMAC SHA256, HMAC SHA384, or HMAC SHA512 as defined in FIPS
+ 1803 [FIPS.1803]. The "int" header parameter values "HS256",
+ "HS384", or "HS512" are used in this case.
+
+ A key of the same size as the hash output (for instance, 256 bits for
+ "HS256") or larger MUST be used with this algorithm.
+
+4.11. Additional Encryption Algorithms and Parameters
Additional algorithms MAY be used to protect JWEs with corresponding
 "alg" (algorithm) and "enc" (encryption method) header parameter
 values being defined to refer to them. New "alg" and "enc" header
 parameter values SHOULD either be defined in the IANA JSON Web
 Encryption Algorithms registry or be a URI that contains a collision
 resistant namespace. In particular, it is permissible to use the
 algorithm identifiers defined in XML Encryption
+ "alg" (algorithm), "enc" (encryption method), and "int" (integrity
+ algorithm) header parameter values being defined to refer to them.
+ New "alg", "enc", and "int" header parameter values SHOULD either be
+ defined in the IANA JSON Web Signature and Encryption Algorithms
+ registry Section 6.2 or be a URI that contains a collision resistant
+ namespace. In particular, it is permissible to use the algorithm
+ identifiers defined in XML Encryption [W3C.RECxmlenccore20021210],
+ XML Encryption 1.1 [W3C.CRxmlenccore120120313], and related
+ specifications as "alg", "enc", and "int" values.
 [W3C.RECxmlenccore20021210], XML Encryption 1.1
 [W3C.CRxmlenccore120110303], and related specifications as "alg"
 and "enc" values.
+ As indicated by the common registry, JWSs and JWEs share a common
+ "alg" value space. The values used by the two specifications MUST be
+ distinct, as the "alg" value MAY be used to determine whether the
+ object is a JWS or JWE.
5. IANA Considerations
+ Likewise, additional reserved header parameter names MAY be defined
+ via the IANA JSON Web Signature and Encryption Header Parameters
+ registry Section 6.1. 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.
 This specification calls for:
+5. Cryptographic Algorithms for JWK
 o A new IANA registry entitled "JSON Web Signature Algorithms" for
 values of the JWS "alg" (algorithm) header parameter is defined in
 Section 3.5. Inclusion in the registry is RFC Required in the RFC
 5226 [RFC5226] sense. The registry will just record the "alg"
 value and a pointer to the RFC that defines it. This
 specification defines inclusion of the algorithm values defined in
 Table 1.
+ A JSON Web Key (JWK) [JWK] is a JSON data structure that represents a
+ public key. A JSON Web Key Set (JWK Set) is a JSON data structure
+ for representing a set of JWKs. This section specifies a set of
+ algorithm families to be used for those public keys and the algorithm
+ family specific parameters for representing those keys.
 o A new IANA registry entitled "JSON Web Encryption Algorithms" for
 values used with the JWE "alg" (algorithm) and "enc" (encryption
 method) header parameters is defined in Section 4.2. Inclusion in
 the registry is RFC Required in the RFC 5226 [RFC5226] sense. The
 registry will record the "alg" or "enc" value and a pointer to the
 RFC that defines it. This specification defines inclusion of the
 algorithm values defined in Table 2 and Table 3.
+5.1. "alg" (Algorithm Family) Parameter Values for JWK
6. Security Considerations
+ The table below is the set of "alg" (algorithm family) parameter
+ values that are defined by this specification for use in JWKs.
 TBD
+ +++
+  alg Parameter Value  Algorithm Family 
+ +++
+  EC  Elliptic Curve [FIPS.1863] key family 
+  RSA  RSA [RFC3447] key family 
+ +++
7. Open Issues and Things To Be Done (TBD)
+5.2. JWK Parameters for Elliptic Curve Keys
 The following items remain to be done in this draft:
+ JWKs can represent Elliptic Curve [FIPS.1863] keys. In this case,
+ the "alg" member value MUST be "EC". Furthermore, these additional
+ members MUST be present:
 o Specify minimum required key sizes for all algorithms.
+5.2.1. "crv" (Curve) Parameter
 o Specify which algorithms require Initialization Vectors (IVs) and
 minimum required lengths for those IVs.
+ The "crv" (curve) member identifies the cryptographic curve used with
+ the key. Values defined by this specification are "P256", "P384"
+ and "P521". Additional "crv" values MAY be used, provided they are
+ understood by implementations using that Elliptic Curve key. The
+ "crv" value is case sensitive. Its value MUST be a string.
 o Since RFC 3447 Section 8 explicitly calls for people NOT to adopt
 RSASSAPKCS1 for new applications and instead requests that people
 transition to RSASSAPSS, we probably need some Security
 Considerations text explaining why RSASSAPKCS1 is being used
 (it's what's commonly implemented) and what the potential
 consequences are.
+5.2.2. "x" (X Coordinate) Parameter
 o Should we define the use of RFC 5649 key wrapping functions, which
 allow arbitrary key sizes, in addition to the current use of RFC
 3394 key wrapping functions, which require that keys be multiples
 of 64 bits? Is this needed in practice?
+ The "x" (x coordinate) member contains the x coordinate for the
+ elliptic curve point. It is represented as the base64url encoding of
+ the coordinate's big endian representation.
 o Decide whether to move the JWK algorithm family definitions "EC"
 and "RSA" here. This would likely result in all the family
 specific parameter definitions also moving here ("crv", "x", "y",
 "mod", "exp"), leaving very little normative text in the JWK spec
 itself. This seems like it would reduce spec readability and so
 was not done.
+5.2.3. "y" (Y Coordinate) Parameter
 o It would be good to say somewhere, in normative language, that
 eventually the algorithms and/or key sizes currently specified
 will no longer be considered sufficiently secure and will be
 removed. Therefore, implementers MUST be prepared for this
 eventuality.
+ The "y" (y coordinate) member contains the y coordinate for the
+ elliptic curve point. It is represented as the base64url encoding of
+ the coordinate's big endian representation.
 o Write the Security Considerations section.
+5.3. JWK Parameters for RSA Keys
8. References
+ JWKs can represent RSA [RFC3447] keys. In this case, the "alg"
+ member value MUST be "RSA". Furthermore, these additional members
+ MUST be present:
8.1. Normative References
+5.3.1. "mod" (Modulus) Parameter
 [FIPS197]
 National Institute of Standards and Technology (NIST),
 "Advanced Encryption Standard (AES)", FIPS PUB 197,
 November 2001.
+ The "mod" (modulus) member contains the modulus value for the RSA
+ public key. It is represented as the base64url encoding of the
+ value's big endian representation.
+
+5.3.2. "exp" (Exponent) Parameter
+
+ The "exp" (exponent) member contains the exponent value for the RSA
+ public key. It is represented as the base64url encoding of the
+ value's big endian representation.
+
+5.4. Additional Key Algorithm Families and Parameters
+
+ Public keys using additional algorithm families MAY be represented
+ using JWK data structures with corresponding "alg" (algorithm family)
+ parameter values being defined to refer to them. New "alg" parameter
+ values SHOULD either be defined in the IANA JSON Web Key Algorithm
+ Families registry Section 6.5 or be a URI that contains a collision
+ resistant namespace.
+
+ Likewise, parameters for representing keys for additional algorithm
+ families or additional key properties SHOULD either be defined in the
+ IANA JSON Web Key Parameters registry Section 6.4 or be a URI that
+ contains a collision resistant namespace.
+
+6. IANA Considerations
+
+6.1. JSON Web Signature and Encryption Header Parameters Registry
+
+ This specification establishes the IANA JSON Web Signature and
+ Encryption Header Parameters registry for reserved JWS and JWE header
+ parameter names. Inclusion in the registry is RFC Required in the
+ RFC 5226 [RFC5226] sense. The registry records the reserved header
+ parameter name and a reference to the RFC that defines it. This
+ specification registers the header parameter names defined in JSON
+ Web Signature (JWS) [JWS], Section 4.1 and JSON Web Encryption (JWE)
+ [JWE], Section 4.1.
+
+6.2. JSON Web Signature and Encryption Algorithms Registry
+
+ This specification establishes the IANA JSON Web Signature and
+ Encryption Algorithms registry for values of the JWS and JWE "alg"
+ (algorithm), "enc" (encryption method), and "int" (integrity
+ algorithm) header parameters. Inclusion in the registry is RFC
+ Required in the RFC 5226 [RFC5226] sense. The registry records the
+ algorithm usage "alg", "enc", or "int", the value, and a pointer to
+ the RFC that defines it. This specification registers the values
+ defined in Section 3.1, Section 4.1, Section 4.2, and Section 4.3.
+
+6.3. JSON Web Signature and Encryption "typ" Values Registry
+
+ This specification establishes the IANA JSON Web Signature and
+ Encryption "typ" Values registry for values of the JWS and JWE "typ"
+ (type) header parameter. Inclusion in the registry is RFC Required
+ in the RFC 5226 [RFC5226] sense. It is RECOMMENDED that all
+ registered "typ" values also register a MIME Media Type RFC 2045
+ [RFC2045] that the registered value is a short name for. The
+ registry records the "typ" value, the MIME type value that it is an
+ abbreviation for (if any), and a pointer to the RFC that defines it.
+
+ MIME Media Type RFC 2045 [RFC2045] values MUST NOT be directly
+ registered as new "typ" values; rather, new "typ" values MAY be
+ registered as short names for MIME types.
+
+6.4. JSON Web Key Parameters Registry
+
+ This specification establishes the IANA JSON Web Key Parameters
+ registry for reserved JWK parameter names. Inclusion in the registry
+ is RFC Required in the RFC 5226 [RFC5226] sense. The registry
+ records the reserved parameter name and a reference to the RFC that
+ defines it. This specification registers the parameter names defined
+ in JSON Web Key (JWK) [JWK], Section 4.2, JSON Web Encryption (JWE)
+ [JWE], Section 4.1, Section 5.2, and Section 5.3.
+
+6.5. JSON Web Key Algorithm Families Registry
+
+ This specification establishes the IANA JSON Web Key Algorithm
+ Families registry for values of the JWK "alg" (algorithm family)
+ parameter. Inclusion in the registry is RFC Required in the RFC 5226
+ [RFC5226] sense. The registry records the "alg" value and a pointer
+ to the RFC that defines it. This specification registers the values
+ defined in Section 5.1.
+
+7. Security Considerations
+
+ The security considerations in the JWS, JWE, and JWK specifications
+ also apply to this specification.
+
+ Eventually the algorithms and/or key sizes currently described in
+ this specification will no longer be considered sufficiently secure
+ and will be removed. Therefore, implementers and deployments must be
+ prepared for this eventuality.
+
+8. Open Issues and Things To Be Done (TBD)
+
+ The following items remain to be done in this draft:
+
+ o Find values for encryption algorithm crossreference table
+ currently listed as "TBD" or determine that they do not exist.
+
+9. References
+
+9.1. Normative References
[FIPS.1803]
National Institute of Standards and Technology, "Secure
Hash Standard (SHS)", FIPS PUB 1803, October 2008.
[FIPS.1863]
National Institute of Standards and Technology, "Digital
Signature Standard (DSS)", FIPS PUB 1863, June 2009.
+ [FIPS.197]
+ National Institute of Standards and Technology (NIST),
+ "Advanced Encryption Standard (AES)", FIPS PUB 197,
+ November 2001.
+
[JWE] Jones, M., Rescorla, E., and J. Hildebrand, "JSON Web
 Encryption (JWE)", March 2012.
+ Encryption (JWE)", May 2012.
+
+ [JWK] Jones, M., "JSON Web Key (JWK)", May 2012.
[JWS] Jones, M., Bradley, J., and N. Sakimura, "JSON Web
 Signature (JWS)", March 2012.
+ Signature (JWS)", May 2012.
 [NIST80038A]
+ [NIST.80038A]
National Institute of Standards and Technology (NIST),
"Recommendation for Block Cipher Modes of Operation",
NIST PUB 80038A, December 2001.
 [NIST80038D]
+ [NIST.80038D]
National Institute of Standards and Technology (NIST),
"Recommendation for Block Cipher Modes of Operation:
Galois/Counter Mode (GCM) and GMAC", NIST PUB 80038D,
December 2001.
 [NIST80056A]
+ [NIST.80056A]
National Institute of Standards and Technology (NIST),
"Recommendation for PairWise Key Establishment Schemes
Using Discrete Logarithm Cryptography (Revised)", NIST PUB
80056A, March 2007.
+ [RFC2045] Freed, N. and N. Borenstein, "Multipurpose Internet Mail
+ Extensions (MIME) Part One: Format of Internet Message
+ Bodies", RFC 2045, November 1996.
+
[RFC2104] Krawczyk, H., Bellare, M., and R. Canetti, "HMAC: Keyed
Hashing for Message Authentication", RFC 2104,
February 1997.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC3394] Schaad, J. and R. Housley, "Advanced Encryption Standard
(AES) Key Wrap Algorithm", RFC 3394, September 2002.
@@ 531,21 +796,21 @@
Standards (PKCS) #1: RSA Cryptography Specifications
Version 2.1", RFC 3447, February 2003.
[RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an
IANA Considerations Section in RFCs", BCP 26, RFC 5226,
May 2008.
[RFC6090] McGrew, D., Igoe, K., and M. Salter, "Fundamental Elliptic
Curve Cryptography Algorithms", RFC 6090, February 2011.
8.2. Informative References
+9.2. Informative References
[CanvasApp]
Facebook, "Canvas Applications", 2010.
[ID.rescorlajsms]
Rescorla, E. and J. Hildebrand, "JavaScript Message
Security Format", draftrescorlajsms00 (work in
progress), March 2011.
[JCA] Oracle, "Java Cryptography Architecture", 2011.
@@ 557,41 +822,49 @@
September 2010.
[MagicSignatures]
Panzer (editor), J., Laurie, B., and D. Balfanz, "Magic
Signatures", January 2011.
[RFC3275] Eastlake, D., Reagle, J., and D. Solo, "(Extensible Markup
Language) XMLSignature Syntax and Processing", RFC 3275,
March 2002.
 [W3C.CRxmlenccore120110303]
 Hirsch, F., Roessler, T., Reagle, J., and D. Eastlake,
+ [W3C.CRxmldsigcore220120124]
+ Eastlake, D., Reagle, J., Yiu, K., Solo, D., Datta, P.,
+ Hirsch, F., Cantor, S., and T. Roessler, "XML Signature
+ Syntax and Processing Version 2.0", World Wide Web
+ Consortium CR CRxmldsigcore220120124, January 2012,
+ .
+
+ [W3C.CRxmlenccore120120313]
+ Eastlake, D., Reagle, J., Roessler, T., and F. Hirsch,
"XML Encryption Syntax and Processing Version 1.1", World
 Wide Web Consortium CR CRxmlenccore120110303,
 March 2011,
 .
+ Wide Web Consortium CR CRxmlenccore120120313,
+ March 2012,
+ .
[W3C.RECxmlenccore20021210]
Eastlake, D. and J. Reagle, "XML Encryption Syntax and
Processing", World Wide Web Consortium Recommendation REC
xmlenccore20021210, December 2002,
.
Appendix A. Digital Signature/HMAC Algorithm Identifier CrossReference
+Appendix A. Digital Signature/MAC Algorithm Identifier CrossReference
This appendix contains a table crossreferencing the digital
 signature and HMAC "alg" (algorithm) values used in this
 specification with the equivalent identifiers used by other standards
 and software packages. See XML DSIG [RFC3275] and Java Cryptography
 Architecture [JCA] for more information about the names defined by
 those documents.
+ signature and MAC "alg" (algorithm) values used in this specification
+ with the equivalent identifiers used by other standards and software
+ packages. See XML DSIG [RFC3275], XML DSIG 2.0
+ [W3C.CRxmldsigcore220120124], and Java Cryptography Architecture
+ [JCA] for more information about the names defined by those
+ documents.
++++++
 Algor  JWS  XML DSIG  JCA  OID 
 ithm     
++++++
 HMAC  HS2  http://www.w3.org/2001/04/  HmacSHA2  1.2.840.113 
 using  56  xmldsigmore#hmacsha256  56  549.2.9 
 SHA2     
 56     
 hash     
@@ 657,30 +930,28 @@
 P521     
 curve     
 and     
 SHA5     
 12     
 hash     
 algo     
 rithm     
++++++
 Table 4: Digital Signature/HMAC Algorithm Identifier CrossReference

Appendix B. Encryption Algorithm Identifier CrossReference
This appendix contains a table crossreferencing the "alg"
(algorithm) and "enc" (encryption method) values used in this
specification with the equivalent identifiers used by other standards
and software packages. See XML Encryption
[W3C.RECxmlenccore20021210], XML Encryption 1.1
 [W3C.CRxmlenccore120110303], and Java Cryptography Architecture
+ [W3C.CRxmlenccore120120313], and Java Cryptography Architecture
[JCA] for more information about the names defined by those
documents.
+++++
 Algorit  JWE  XML ENC  JCA 
 hm    
+++++
 RSA  RSA1_  http://www.w3.org/2001/04  RSA/ECB/PKCS1Paddin 
 using  5  /xmlenc#rsa1_5  g 
 RSAPKC    
@@ 730,107 +1001,142 @@
 ) Key    
 Wrap    
 Algo    
 rithm R    
 FC 339    
 4 [RF    
 C3394]    
 using25    
 6 bitke    
 ys    
  Advance  A512K  http://www.w3.org/2001/04  TBD 
  d  W  /xmlenc#kwaes512  
  Encryp    
  tion    
  Stand    
  ard(AES    
  ) Key    
  Wrap    
  Algo    
  rithm R    
  FC 339    
  4 [RF    
  C3394]    
  using51    
  2 bitke    
  ys    
 Advance  A128C  http://www.w3.org/2001/04  AES/CBC/PKCS5Paddin 
 d  BC  /xmlenc#aes128cbc  g 
 Encryp    
 tion    
 Stand    
 ard(AES    
 ) usin    
 g 128    
 bitkeys    
 inCiph    
 er Bloc    
 k Chai    
  ningmod    
  e    
+  ning(CB    
+  C) mod    
+  e usi    
+  ng PKC    
+  S #5pad    
+  ding    
 Advance  A256C  http://www.w3.org/2001/04  AES/CBC/PKCS5Paddin 
 d  BC  /xmlenc#aes256cbc  g 
 Encryp    
 tion    
 Stand    
 ard(AES    
 ) usin    
 g 256    
 bitkeys    
 inCiph    
 er Bloc    
 k Chai    
  ningmod    
  e    
+  ning(CB    
+  C) mod    
+  e usi    
+  ng PKC    
+  S #5pad    
+  ding    
 Advance  A128G  http://www.w3.org/2009/xm  AES/GCM/NoPadding 
 d  CM  lenc11#aes128gcm  
 Encryp    
 tion    
 Stand    
 ard(AES    
 ) usin    
 g 128    
 bitkeys    
 inGalo    
 is/Coun    
 ter Mod    
  e    
+  e (GC    
+  M)    
 Advance  A256G  http://www.w3.org/2009/xm  AES/GCM/NoPadding 
 d  CM  lenc11#aes256gcm  
 Encryp    
 tion    
 Stand    
 ard(AES    
 ) usin    
 g 256    
 bitkeys    
 inGalo    
 is/Coun    
 ter Mod    
  e    
+  e (GC    
+  M)    
+++++
 Table 5: Encryption Algorithm Identifier CrossReference

Appendix C. Acknowledgements
Solutions for signing and encrypting JSON content were previously
explored by Magic Signatures [MagicSignatures], JSON Simple Sign
[JSS], Canvas Applications [CanvasApp], JSON Simple Encryption [JSE],
and JavaScript Message Security Format [ID.rescorlajsms], all of
which influenced this draft. Dirk Balfanz, John Bradley, Yaron Y.
Goland, John Panzer, Nat Sakimura, and Paul Tarjan all made
significant contributions to the design of this specification and its
related specifications.
Appendix D. Document History
+ 02
+
+ o For AES GCM, use the "additional authenticated data" parameter to
+ provide integrity for the header, encrypted key, and ciphertext
+ and use the resulting "authentication tag" value as the JWE
+ Integrity Value.
+
+ o Defined minimum required key sizes for algorithms without
+ specified key sizes.
+
+ o Defined KDF output key sizes.
+
+ o Specified the use of PKCS #5 padding with AESCBC.
+
+ o Generalized text to allow key agreement to be employed as an
+ alternative to key wrapping or key encryption.
+
+ o Clarified that ECDHES is a key agreement algorithm.
+
+ o Required implementation of AES128KW and AES256KW.
+
+ o Removed the use of "A128GCM" and "A256GCM" for key wrapping.
+
+ o Removed "A512KW" since it turns out that it's not a standard
+ algorithm.
+
+ o Clarified the relationship between "typ" header parameter values
+ and MIME types.
+
+ o Generalized language to refer to Message Authentication Codes
+ (MACs) rather than Hashbased Message Authentication Codes (HMACs)
+ unless in a context specific to HMAC algorithms.
+
+ o Established registries: JSON Web Signature and Encryption Header
+ Parameters, JSON Web Signature and Encryption Algorithms, JSON Web
+ Signature and Encryption "typ" Values, JSON Web Key Parameters,
+ and JSON Web Key Algorithm Families.
+
+ o Moved algorithmspecific definitions from JWK to JWA.
+
+ o Reformatted to give each member definition its own section
+ heading.
+
01
o Moved definition of "alg":"none" for JWSs here from the JWT
specification since this functionality is likely to be useful in
more contexts that just for JWTs.
o Added Advanced Encryption Standard (AES) Key Wrap Algorithm using
512 bit keys ("A512KW").
o Added text "Alternatively, the Encoded JWS Signature MAY be