Proov

KSI Technology is a blockchain system called Keyless Signature Infrastructure (KSI). It references five academic papers on provably secure timestamping schemes and hash-tree time-stamping using hash functions. The papers provide the first proof that hash-then-publish time-stamping is secure if the hash function is collision resistant, optimally tight security proofs for the hash-then-publish approach, security proofs for hash tree time-stamping using small output hash functions, how to build global distributed hash-trees, and efficient record-level keyless signatures for audit logs.