RFC 1423 (rfc1423) - Page 2 of 14

Privacy Enhancement for Internet Electronic Mail: Part III: Algorithms, Modes, and Identifiers

RFC 1423         PEM: Algorithms, Modes and Identifiers    February 1993


   Task Force's Privacy Enhanced Mail Working Group (IETF PEM WG).  John
   Linn contributed significantly to the predecessor of this document
   (RFC 1115).  I would like to thank the members of the PSRG and PEM
   WG, as well as all participants in discussions on the "pem-
   " mailing list, for their contributions to this document.

Table of Contents

      1.  Message Encryption Algorithms ....................... 2
      1.1  DES in CBC Mode (DES-CBC) .......................... 2
      2.  Message Integrity Check Algorithms .................. 4
      2.1  RSA-MD2 Message Digest Algorithm ................... 4
      2.2  RSA-MD5 Message Digest Algorithm ................... 5
      3.  Symmetric Key Management Algorithms ................. 6
      3.1  DES in ECB mode (DES-ECB) .......................... 6
      3.2  DES in EDE mode (DES-EDE) .......................... 7
      4.  Asymmetric Key Management Algorithms ................ 7
      4.1  Asymmetric Keys .................................... 7
      4.1.1  RSA Keys ......................................... 7
      4.2  Asymmetric Encryption Algorithms ..................  9
      4.2.1  RSAEncryption ...................................  9
      4.3  Asymmetric Signature Algorithms ................... 10
      4.3.1  md2WithRSAEncryption ............................ 11
      5.  Descriptive Grammar ................................ 11
      References ............................................. 12
      Patent Statement ....................................... 13
      Security Considerations ................................ 14
      Author's Address ....................................... 14

1.  Message Encryption Algorithms

   This section identifies the alternative message encryption algorithms
   and modes that shall be used to encrypt message text and, when
   asymmetric key management is employed in an ENCRYPTED PEM message, for
   encryption of message signatures.  Character string identifiers are
   assigned and any parameters required by the message encryption
   algorithm are defined for incorporation in an encapsulated "DEK-
   Info:" header field.

   Only one alternative is currently defined in this category.

1.1  DES in CBC Mode (DES-CBC)

   Message text and, if required, message signatures are encrypted using
   the Data Encryption Standard (DES) algorithm in the Cipher Block
   Chaining (CBC) mode of operation.  The DES algorithm is defined in
   FIPS PUB 46-1 [1], and is equivalent to the Data Encryption Algorithm
   (DEA) provided in ANSI X3.92-1981 [2].  The CBC mode of operation of



Balenson