RFC 3447: Public-Key Cryptography Standards (PKCS) #1: RSA Cryptography Specifications Version 2.1 | RFC Editor

Skip to content Primary navigationThe RFC SeriesFor AuthorsAbout UsHomeRFC 3447 View as: Plain Text, Compact HTML Info RFC 3447: Public-Key Cryptography Standards (PKCS) #1: RSA Cryptography Specifications Version 2.1RSAFebruary 2003. J. Jonsson, B. KaliskiInformationalSubscribe3 subscribed Add to Set Added to 1 Set Read aloud This RFC is now obsolete, see RFC 8017.Network Working Group J. Jonsson Request for Comments: 3447 B. Kaliski Obsoletes: 2437 RSA Laboratories Category: Informational February 2003 Public-Key Cryptography Standards (PKCS) #1: RSA Cryptography Specifications Version 2.1 Status of this Memo This memo provides information for the Internet community. It does not specify an Internet standard of any kind. Distribution of this memo is unlimited. Copyright Notice Copyright (C) The Internet Society (2003). All Rights Reserved. Abstract This memo represents a republication of PKCS #1 v2.1 from RSA Laboratories' Public-Key Cryptography Standards (PKCS) series, and change control is retained within the PKCS process. The body of this document is taken directly from the PKCS #1 v2.1 document, with certain corrections made during the publication process. Table of Contents 1. Introduction...............................................2 2. Notation...................................................3 3. Key types..................................................6 3.1 RSA public key..........................................6 3.2 RSA private key.........................................7 4. Data conversion primitives.................................8 4.1 I2OSP...................................................9 4.2 OS2IP...................................................9 5. Cryptographic primitives..................................10 5.1 Encryption and decryption primitives...................10 5.2 Signature and verification primitives..................12 6. Overview of schemes.......................................14 7. Encryption schemes........................................15 7.1 RSAES-OAEP.............................................16 7.2 RSAES-PKCS1-v1_5.......................................23 8. Signature schemes with appendix...........................27 8.1 RSASSA-PSS.............................................29 8.2 RSASSA-PKCS1-v1_5......................................32 9. Encoding methods for signatures with appendix.............35 Jonsson & Kaliski Informational [Page 1] RFC 3447 PKCS #1: RSA Cryptography Specifications February 2003 9.1 EMSA-PSS...............................................36 9.2 EMSA-PKCS1-v1_5........................................41 Appendix A. ASN.1 syntax...........................................44 A.1 RSA key representation.................................44 A.2 Scheme identification..................................46 Appendix B. Supporting techniques..................................52 B.1 Hash functions.........................................52 B.2 Mask generation functions..............................54 Appendix C. ASN.1 module...........................................56 Appendix D. Intellectual Property Considerations...................63 Appendix E. Revision history.......................................64 Appendix F. References.............................................65 Appendix G. About PKCS.............................................70 Appendix H. Corrections Made During RFC Publication Process........70 Security Considerations............................................70 Acknowledgements...................................................71 Authors' Addresses.................................................71 Full Copyright Statement...........................................72 1. Introduction This document provides recommendations for the implementation of public-key cryptography based on the RSA algorithm [42], covering the following aspects: * Cryptographic primitives * Encryption schemes * Signature schemes with appendix * ASN.1 syntax for representing keys and for identifying the schemes The recommendations are intended for general application within computer and communications systems, and as such include a fair amount of flexibility. It is expected that application standards based on these specifications may include additional constraints. The recommendations are intended to be compatible with the standard IEEE-1363-2000 [26] and draft standards currently being developed by the ANSI X9F1 [1] and IEEE P1363 [27] working groups. This document supersedes PKCS #1 version 2.0 [35][44] but includes compatible techniques. Jonsson & Kaliski Informational [Page 2] RFC 3447 PKCS #1: RSA Cryptography Specifications February 2003 The organization of this document is as follows: * Section 1 is an introduction. * Section 2 defines some notation used in this document. * Section 3 defines the RSA public and private key types. * Sections 4 and 5 define several primitives, or basic mathematical operations. Data conversion primitives are in Section 4, and cryptographic primitives (encryption-decryption, signature- verification) are in Section 5. * Sections 6, 7, and 8 deal with the encryption and signature schemes in this document. Section 6 gives an overview. Along with the methods found in PKCS #1 v1.5, Section 7 defines an OAEP-based [3] encryption scheme and Section 8 defines a PSS-based [4][5] signature scheme with appendix. * Section 9 defines the encoding methods for the signature schemes in Section 8. * Appendix A defines the ASN.1 syntax for the keys defined in Section 3 and the schemes in Sections 7 and 8. * Appendix B defines the hash functions and the mask generation function used in this document, including ASN.1 syntax for the techniques. * Appendix C gives an ASN.1 module. * Appendices D, E, F and G cover intellectual property issues, outline the revision history of PKCS #1, give references to other publications and standards, and provide general information about the Public-Key Cryptography Standards. 2. Notation c ci