Encryption Technologies Explained: From AES to Digital Signatures and Tokenisation

Cryptography relies on two main encryption types: symmetric encryption, which uses a single shared key (AES, 3DES) for bulk data, and asymmetric encryption, which uses a public-private key pair (RSA, ECC) for secure communication and identity verification. Hashing algorithms like SHA-256 and SHA-3 generate fixed-size, irreversible outputs used to ensure data integrity, while digital signatures combine hashing and asymmetric encryption to provide authentication, integrity, and non-repudiation. Data at rest in systems like core banking is protected using AES-256 Transparent Data Encryption, while data in transit is secured via TLS 1.2 or 1.3. Tokenisation replaces sensitive data such as card numbers with non-sensitive tokens stored in a secure vault, a practice essential for PCI-DSS compliance, whereas data masking retains format while hiding actual values. In India, IDRBT provides the digital certificate infrastructure and secure network backbone for critical payment systems like RTGS, and ISO 9564 governs PIN block formatting standards used in ATM and POS transactions.