ECDSA (Elliptic Curve Digital Signature Algorithm) is a public-key electronic digital signature algorithm. In its logic of operation it is close to classic DSA, but it is built not over a field of integers but in a group of points on an elliptic curve. This approach provides high cryptographic strength with a relatively small key length, which is important for distributed networks with millions of operations.

In cryptocurrencies, ECDSA solves a key task: to prove that a transaction was initiated by the actual owner of the funds, without revealing the private key. The user signs the transaction data with their private key, and any network participant can verify the signature using the corresponding public key. If the signature is valid, the nodes accept the transfer as valid.

Where ECDSA is used

• Signing transactions in the Bitcoin protocol and compatible networks.
• Confirming ownership of an address and the funds on it.
• Protection against forgery and the reuse of operations.

Thanks to the combination of reliability and efficiency, ECDSA became one of the basic cryptographic tools of the blockchain. The security of the system depends directly on how reliably a user stores their private key.