<p>Quantum cryptography is a new paradigm of cryptographic protection of information. It relies on the laws of quantum mechanics and the properties of quantum information carriers — photons — to overcome the limitations of classical cryptographic protocols and improve their security up to the information-theoretic level. This paper presents a general overview and analysis of modern quantum information security technologies, including protocols for quantum key distribution, quantum secure direct communication, and quantum secret sharing. It also reviews other areas of quantum cryptography, namely, quantum digital signatures, quantum bit commitment, and quantum steganography. The advantages and limitations of quantum cryptographic protocols are examined, along with the prospects and challenges of their practical implementation. A brief overview of the quantum physics principles underlying their security is provided.</p>