What technology ensures security in blockchain transactions?

Public key cryptography is fundamental to ensuring security in blockchain transactions. This cryptographic framework uses paired public and private keys to manage identities and enable secure transactions. When a user initiates a transaction on the blockchain, they sign it with their private key. This signatory action creates a unique digital signature that verifies the authenticity of the transaction. Other participants on the network can then use the corresponding public key to confirm that the signature matches the claimed sender, ensuring that the transaction hasn't been altered and that it genuinely originated from the stated sender.

By incorporating this cryptographic method, blockchain technology effectively prevents unauthorized access and fraud, providing a robust security model that underpins public and private blockchain systems alike. This reliance on cryptographic security distinguishes blockchain from other systems, such as cloud storage and traditional database management systems, which may not offer the same decentralized security properties.