| bgcolor="#BBF" colspan="4" | PKCS Standards Summary |
| !! Version !! Name !! Comments |
| PKCS#1 | align="center" | 2.1 | RSA Cryptography Standard | See RFC 3447. Defines the format of RSA encryption. |
| PKCS#2 | align="center" | - | Withdrawn | No longer active. Covered RSA encryption of message digests, but was merged into PKCS#1. |
| PKCS#3 | align="center" | 1.4 | Diffie-Hellman Key Agreement Standard | |
| PKCS#4 | align="center" | - | Withdrawn | No longer active. Covered RSA key syntax, but was merged into PKCS#1. |
| PKCS#5 | align="center" | 2.0 | Password-based Encryption Standard | See RFC 2898 and PBKDF2. |
| PKCS#6 | align="center" | 1.5 | Extended-Certificate Syntax Standard | Defines extensions to the old v1 X.509 certificate specification. Obsoleted by v3 of the same. |
| PKCS#7 | align="center" | 1.5 | Cryptographic Message Syntax Standard | See RFC 2315. Forms the basis for S/MIME; used to sign and/or encrypt messages under a PKI. Used also for certificate dissemination (for instance as a response to a PKCS#10 message). |
| PKCS#8 | align="center" | 1.2 | Private-Key Information Syntax Standard | |
| PKCS#9 | align="center" | 2.0 | Selected Attribute Types | |
| PKCS#10 | align="center" | 1.7 | Certification Request Standard | See RFC 2986. Format of messages sent to a Certification Authority to request certification of a key pair. See certificate signing request. |
| PKCS#11 | align="center" | 2.20 | Cryptographic Token Interface (cryptoki) | An API defining a generic interface to cryptographic tokens (see also Hardware Security Module). |
| PKCS#12 | align="center" | 1.0 | Personal Information Exchange Syntax Standard | Defines a file format commonly used to store private keys with accompanying Public key certificates protected with a password-based symmetric key. |
| PKCS#13 | align="center" | – | Elliptic Curve Cryptography Standard | (Under development) |
| PKCS#14 | align="center" | – | Pseudo-random Number Generation | (Under development) |
| PKCS#15 | align="center" | – | Cryptographic Token Information Format Standard | (Retired) |