Cryptography
RSA Algorithm
Also known as: RSA, Rivest–Shamir–Adleman
Definition
A public-key algorithm by Rivest, Shamir and Adleman (1977) whose security rests on the difficulty of factoring the product of two large prime numbers.
Examples
- Most TLS server certificates issued before 2020 use RSA-2048 or RSA-3072 keys.
- GPG email signatures often use 4096-bit RSA key pairs.
Related terms
Asymmetric Encryption
A cryptographic scheme that uses mathematically linked key pairs — a public key for encryption and a private key for decryption — to enable secure communication without prior secret sharing.
Public-Key Cryptography
A branch of cryptography that uses paired public and private keys to enable encryption, key exchange, digital signatures, and authentication without a pre-shared secret.
Elliptic Curve Cryptography (ECC)
A family of public-key algorithms based on the algebraic structure of elliptic curves over finite fields, offering equivalent security to RSA with much smaller keys.
Digital Signature
A public-key cryptographic mechanism that proves the authenticity, integrity and non-repudiation of a message or document.
Post-Quantum Cryptography
Classical cryptographic algorithms designed to remain secure against attacks by both classical and large-scale quantum computers.
Public Key
The freely distributable half of an asymmetric key pair, used to encrypt messages for its owner or to verify digital signatures produced by the matching private key.