Trapdoor Function Security

Security under chosen ciphertext attack cca security 39 45 20.

Trapdoor function security.

Also called a manhole or trapdoor a backdoor is a concealed means of bypassing. Check pad on decryption. In mathematical terms if f is a trapdoor function there exists some secret information y such that given f x and y it is easy. The main building block of our construction is a novel primitive called sampleable range trapdoor function that is a trapdoor.

Moreover the trap door is often activated by an event or a normal action. Trapdoor function i e permutation and doubly enhanced lossy correlated product secure was required and critical for achieving chosen ciphertext security leaving open the problem of building chosen ciphertext secure encryption by only assuming injective trapdoor functions. Page 13 thm fops 01. Additionally what is backdoor and trapdoor.

Lossy trapdoor functions ltfs introduced by peiker and waters in stoc 08 are functions that may be working in another injective mode or a lossy mode. Trapdoor functions which informally are hard to invert unless one possesses some secret trapdoor information conceptually date back to the seminal paper of diffie and hellman 18 and were first realized by the rsa function of rivest shamir and. The use of the word trapdoor here clearly coincides with more recent definitions of a backdoor. Click to see full answer.

Use sha 256 for h and g. This paper studies lossy trapdoor functions with i tight security i. A trapdoor function is a function that is easy to compute in one direction yet difficult to compute in the opposite direction finding its inverse without special information called the trapdoor trapdoor functions are widely used in cryptography. In mathematical terms if f is a trapdoor function then there exists some secret information t such that given f x and t it is easy to.

Given such a function key it is impossible to distinguish an injective key from a lossy key for any probabilistic polynomial time adversary. Similarly it is asked what is trap door in security. However since the advent of public key cryptography the term trapdoor has acquired a different meaning see trapdoor function and thus the term backdoor is now preferred only after the term trapdoor went out of use. Oaep br94 h m 01 00 0 rand.

A trap door is an entrance point in an information processing system which circumvents the normal safety measures. G plaintext to encrypt with rsa reject ct if invalid.