Cryptographic Modules Testing laboratories perform validation testing of cryptographic modules. Cryptographic hash functions are a third type of cryptographic algorithm. It is based on using a cryptographic hash or symmetric encryption algorithm. Quantum cryptography is the science of exploiting quantum mechanical properties to perform cryptographic tasks. Password verification commonly relies on cryptographic hashes. Checksum functions are related to hash functions, fingerprints, randomization functions, and cryptographic hash functions. Key management refers to management of cryptographic keys in a cryptosystem. Malleability is a property of some cryptographic algorithms. The following tables compare technical information for compression functions of cryptographic hash functions. This technique was used to successfully attack GnuPG, AES and other cryptographic implementations. Instead, most RSA implementations use an alternate technique known as cryptographic blinding. Schneier has been involved in the creation of many cryptographic algorithms. They can also be useful as initialization vectors and in cryptographic hash functions. Some HSM systems are also hardware cryptographic accelerators.