hashketjua
Hashketjua, or hash chain, is a cryptographic construction consisting of a sequence of values produced by iteratively applying a cryptographic hash function to a starting seed. Each element is the hash of the previous one, forming a chain that grows toward a fixed anchor value that may be published in advance. The chain provides a source of one-time values and commitments for authentication and integrity protocols.
Construction and operation: Given a hash function H and a seed s0, define s1 = H(s0), s2 =
Applications: Hashketjua have been used in one-time password systems such as S/Key, where users authenticate by
Security and limitations: The security rests on the preimage resistance of the hash function. If an attacker
Variants: Some approaches reveal values in reverse order, use salting, or pair hash chains with other primitives
References: See standard cryptographic literature on hash chains and one-time password schemes.