Skye: An Expanding PRF based Fast KDF and its Applications
Amit Singh Bhati, Antonín Dufka, Elena Andreeva, Arnab Roy, Bart Preneel · 2024
A Key Derivation Function (KDF) generates a uniform and highly random key-stream from weakly random key material. KDFs are broadly used in various security protocols such as digital signatures and key exchange protocols. HKDF, the most deployed KDF in practice, is based on the extract-then-expand paradigm. It is presently used, among others, in the Signal Protocol for end-to-end encrypted messaging.