KMAC
KMAC is a Keccak-based message authentication code defined in NIST SP 800-185 — a sponge-native replacement for HMAC that needs no nested double hashing.
Purpose
Provides a standardized MAC based on SHA-3, more efficient than HMAC-SHA3 (single sponge pass) with arbitrary-length output support.
Mechanism
cSHAKE128/256 absorbs key K as the first block followed by message M, outputting L bytes. KMAC(K, M, L, S) = cSHAKE(M, L, "KMAC", S, K_prefix). No nested double pass as in HMAC.
Use cases
- SHA-3 message authentication
- Standardized MAC
- Efficient sponge MAC
Related tools
SHA-3 / Keccak Hash
Compute SHA-3 (224/256/384/512) and Keccak-256 hashes. Free, private, and 100% client-side. TOOL
HMAC Generator
Generate HMAC (Keyed-Hash Message Authentication Code) with SHA-1/256/512. Free, private, and 100% client-side. TOOL
Hash Calculator
Compute MD5, SHA-1, SHA-256, or SHA-512 hashes with hex or Base64 output. Free, private, and 100% client-side. TOOL