Cryptography (cryptography) is a scientific discipline about methods of transforming and protecting information. Its tasks are to ensure the confidentiality of data, to confirm its integrity and authenticity, and to make possible the secure exchange of messages in an untrusted environment. The very word cryptocurrency emphasizes that such monetary systems are based precisely on cryptographic algorithms.

The role of cryptography in the blockchain

In the blockchain, cryptography solves several tasks at once. Hash functions link blocks into a single immutable chain: changing even one character in the data completely changes the hash and makes a substitution noticeable. Asymmetric encryption with a pair of a public and a private key allows the owner to sign transactions without revealing the secret key, and any network participant to verify the authenticity of that signature.

• Hashing — ensures the integrity and immutability of records.
• Digital signatures — confirm the authorship of transactions.
• Public and private keys — control access to assets.

Thanks to cryptography, participants in a decentralized network can trust the system as a whole without trusting one another personally. It is precisely the reliability of mathematical methods, rather than the reputation of an intermediary, that guarantees the security of operations.