What is "pkcs"

In cryptography, PKCS stands for "Public Key Cryptography Standards". These are a group of public-key cryptography standards devised and published by RSA Security Inc, starting in the early 1990s. The company published the standards to promote the use of the cryptography techniques to which they had patents, such as the RSA algorithm, the Schnorr signature algorithm and several others. Though not industry standards (because the company retained control over them), some of the standards in recent years have begun to move into the " standards-track" processes of relevant standards organizations such as the IETF and the PKIX working-group.

PKCS Standards Summary

Version

Name

Comments

PKCS #1

2.2

RSA Cryptography Standard

{{cite web

title = PKCS #1: RSA Cryptography Standard

PKCS #2

-

Withdrawn

No longer active . Covered RSA encryption of message digests; subsequently merged into PKCS #1.

PKCS #3

1.4

Diffie–Hellman Key Agreement Standard

{{cite web

title = PKCS #3: Diffie-Hellman Key Agreement Standard

PKCS #4

-

Withdrawn

No longer active . Covered RSA key syntax; subsequently merged into PKCS #1.

PKCS #5

2.0

Password-based Encryption Standard

{{cite web

title = PKCS #5: Password-Based Cryptography Standard

PKCS #6

1.5

Extended-Certificate Syntax Standard

{{cite web

title = PKCS #6: Extended-Certificate Syntax Standard

PKCS #7

1.5

Cryptographic Message Syntax Standard

{{cite web

title = PKCS #7: Cryptographic Message Syntax Standard

PKCS #8

1.2

Private-Key Information Syntax Standard

{{cite web

title = PKCS #8: Private-Key Information Syntax Standard

PKCS #9

2.0

Selected Attribute Types

{{cite web

title = PKCS #9: Selected Attribute Types

PKCS #10

1.7

Certification Request Standard

{{cite web

title = PKCS #10: Certification Request Syntax Standard

PKCS #11

2.40

Cryptographic Token Interface

{{cite web

title = PKCS #11: Cryptographic Token Interface Standard

PKCS #12

1.1

Personal Information Exchange Syntax Standard

| See RFC 7292. Defines a file format commonly used to store private keys with accompanying public key certificates, protected with a password-based symmetric key. PFX is a predecessor to PKCS #12.

This container format can contain multiple embedded objects, such as multiple certificates. Usually protected/encrypted with a password. Usable as a format for the Java key store and to establish client authentication certificates in Mozilla Firefox. Usable by Apache Tomcat.

PKCS #13

–

Elliptic Curve Cryptography Standard

| (Apparently abandoned, only reference is a proposal from 1998.)

{{cite web

PKCS #14

–

Pseudo-random Number Generation

(Apparently abandoned, no documents exist.)

PKCS #15

1.1

Cryptographic Token Information Format Standard

{{cite web

title = PKCS #15: Cryptographic Token Information Format Standard