trapdoor

Etymology

trap + door

noun

1. A hinged or sliding door set into a floor or ceiling.
2. (theater) Such a trap set into the floor of a stage to allow fast exits and entrances.
3. (computing) A secret method of obtaining access to a program or online system; a backdoor.
4. (mathematics, cryptography) The special information that permits the inverse of a trapdoor function to be easily computed.
5. (mining) A door in a level for regulating the ventilating current; a weather door.

verb

1. (cryptography, transitive) To subvert (a cryptographic scheme) by means of a secret parameter that makes the trapdoor function easy to compute.