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Showing posts from July, 2014

Quantum cryptography

Quantum cryptography  describes the use of  quantum mechanical  effects (in particular  quantum communication  and  quantum computation ) to perform  cryptographic  tasks or to break cryptographic systems. Well-known examples of quantum cryptography are the use of quantum communication to exchange a key securely ( quantum key distribution ) and the hypothetical use of quantum computers that would allow the breaking of various popular  public-key encryption  and  signature  schemes (e.g.,  RSA  and  ElGamal ). The advantage of quantum cryptography lies in the fact that it allows the completion of various cryptographic tasks that are proven or conjectured to be impossible using only classical (i.e. non-quantum) communication (see below for examples). For example, quantum mechanics guarantees that measuring quantum data disturbs that data; this can be used to detect eavesdropping in quantum key distribution.