Cryptography
Asymmetric Encryption
Also known as: Public-key encryption
Definition
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.
Examples
- TLS uses RSA or ECDHE to establish a symmetric session key.
- PGP/GPG encrypts an email body to the recipient's public key.
Related terms
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.
RSA Algorithm
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.
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.
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.
Private Key
The secret half of an asymmetric key pair, used to decrypt ciphertext addressed to its owner or to create digital signatures that prove the owner's identity.
Diffie–Hellman Key Exchange
A public-key protocol that lets two parties derive a shared secret over an insecure channel without ever transmitting it, based on the difficulty of the discrete logarithm problem.