PKCS

RFC 2314 - PKCS #10: Certification Request Syntax Version 1.5
This document describes the PKCS #10 format, a syntax for certification requests. (B. Kaliski / RSA Laboratories East)
http://tools.ietf.org/html/rfc2314

RFC 2315 - PKCS #7: Cryptographic Message Syntax Version 1.5
This document describes a general syntax for data that may have cryptography applied to it, such as digital signatures and digital envelopes. (B. Kaliski / RSA Laboratories, East)
http://tools.ietf.org/html/rfc2315

RFC 2437 - PKCS #1: RSA Cryptography Specifications Version 2.0
This document provides recommendations for the implementation of public-key cryptography based on the RSA algorithm. (B. Kaliski, J. Staddon / RSA Laboratories)
http://tools.ietf.org/html/rfc2437

RFC 2313 - PKCS #1: RSA Encryption Version 1.5
This document describes a method for encrypting data using the RSA public-key cryptosystem. (B. Kaliski / RSA Laboratories East)
http://tools.ietf.org/html/rfc2313