Editing Cramer–Shoup cryptosystem (section)

{{Short description|Asymmetric key encryption algorithm}}
The '''Cramer–Shoup system''' is an [[asymmetric cryptography|asymmetric]] key encryption algorithm, and was the first efficient scheme proven to be secure against adaptive chosen ciphertext attack using standard cryptographic assumptions. Its security is based on the computational intractability (widely assumed, but not proved) of the [[Decisional Diffie–Hellman assumption]]. Developed by [[Ronald Cramer]] and [[Victor Shoup]] in 1998, it is an extension of the [[ElGamal]] cryptosystem.  In contrast to ElGamal, which is extremely malleable, Cramer–Shoup adds other elements to ensure non-malleability even against a resourceful attacker.  This non-malleability is achieved through the use of a [[universal one-way hash function]] and additional computations, resulting in a ciphertext which is twice as large as in ElGamal.