Quantum cryptography is a technique for secure communication that makes use of the principles of quantum mechanics. It allows two parties to generate a shared secret key that can be used to encrypt and decrypt messages. Quantum cryptography is often used in conjunction with other security measures, such as digital signatures, to provide a high level of security.
Some of the emerging trends in quantum cryptography include the use of quantum key distribution (QKD) for secure communications, the use of quantum computers for factorization and other cryptographic algorithms, and the use of quantum repeaters for long-distance quantum communications.