Public Key Cryptography Standards (PKCS) are a group of public-key cryptography intervendor standards first developed by RSA Security, with involvement from Apple, Digital, Lotus Software, Microsoft, MIT, Nothern Telecom, and Sun Microsystems, first published in June 1991.
The PKCS series of standards began development internally at RSA Laboratories in March 1991 with the "broad design goals" of maintaining compatibility with existing Privacy-Enhanced Mail (PEM) protocol certificates, allow handling of arbitrary data, adding richer information in certificate attributes, supporting Diffie-Hellman key exchange, and creating protocols to be some day incorporated into International Telecommunication Union X.200 standards by basing it on existing ITU-T standards such as ASN.1 and BER. PKCS then taken by RSA to the US National Institute of Standards and Technology's Open Systems Interconnection Workshop, an organization created in 1983 by NIST at the request of industry to provide a forum for industry co-operation in computer interconnection protocols. Development of the PKCS protocols was undertaken in the 1991 sessions of the OSI Workshop under the Security Special Interest Group chaired by Trusted Information Systems. However, PKCS did not appear in the final OSI Workshop yearly publication
and was instead published as an OSI working document, the first publicly available version of the protocols. Though not industry standards because the company retained control over them, some of the standards have moved into the "standards track" processes of relevant standards organizations since May 1997, such as the IETF and the PKIX working group.
Key Updates (2023âÂÂ2025):