Overview [1]#

Key Derivation Function (KDF) is a Function that derives one or more Cryptographic Keys from a secret value such as a master Cryptographic Key, a password, or a passphrase using a pseudorandom number generator.

Key Derivation Functions can be used to stretch keys into longer Cryptographic Key or to obtain Cryptographic Keys of a required format, such as converting a group element that is the result of a Diffie-Hellman key-exchange into a Symmetric Key for use with AES. Keyed-Hash Message Authentication Codes are popular examples of pseudorandom number generator functions used for Key Derivation Function.

More Information#

There might be more information for this subject on one of the following:

• Double Ratchet Algorithm
• KDF
• Key Generation
• PBKDF2
• PKCS5
• Password-Based Key Derivation Function
• Shared Secret
• TLS 1.3

---

• [#1] - Key derivation function - based on data observed:2015-05-18