Quantum Cryptography

From the early days of communications, the problem of secrecy and protection of messages from adversaries  has been an important issue. Complicated methods for encryption and decryption of messages,  have been developed over a long time, forming a subject which is called classical cryptography. Quantum mechanics revolutionizes these methods in interesting ways which draw their power not from mathematics but from physical properties of nature. In this talk, I briefly review the basic ideas of  classical and quantum cryptography and explain in some detail some of the recent advances in this field.