RSA Laboratories

Public-Key Cryptography Standards (PKCS)

The Public-Key Cryptography Standards are specifications produced by RSA Laboratories in cooperation with secure systems developers worldwide for the purpose of accelerating the deployment of public-key cryptography. First published in 1991 as a result of meetings with a small group of early adopters of public-key technology, the PKCS documents have become widely referenced and implemented. Contributions from the PKCS series have become part of many formal and de facto standards, including ANSI X9 documents, PKIX, SET, S/MIME, and SSL.

Further development of PKCS occurs through mailing list discussions and occasional workshops, and suggestions for improvement are welcome. For more information, please contact us.

The draft Version 2.30 of the PKCS #11 specification is now available for 30-day public review. The public review will continue through Wednesday 28-Oct-2009. Please send all comments to

See the PKCS #11 page for links to the draft documents.

Contributions for PKCS are welcome! Please read our contribution agreement.

Note: PKCS #2 and PKCS #4 have been incorporated into PKCS #1