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Trapdoor Hashing

Definition

Trapdoor hashing refers to a hash function where reversing the hash is computationally feasible only with specific secret information. This specialized cryptographic function produces a fixed-size output from an arbitrary input, similar to standard hash functions, but includes a hidden “trapdoor.” Knowing this trapdoor information allows for efficient computation of a preimage for a given hash output, a task otherwise infeasible. Without the secret, it behaves as a one-way hash, providing security.