Asymmetric Encryption
What is Asymmetric Encryption?
Asymmetric EncryptionA 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.
Asymmetric (public-key) encryption uses a key pair: a public key, freely distributable, and a private key, kept secret by its owner. Anything encrypted with the public key can only be decrypted with the matching private key, which solves the key-distribution problem of symmetric cryptography. Common algorithms include RSA (based on integer factorization), ElGamal and ECIES (based on the discrete logarithm), and modern post-quantum schemes such as ML-KEM (Kyber). Asymmetric encryption is computationally expensive, so in practice it is used to transport or agree upon a symmetric session key — a pattern called hybrid encryption — which then encrypts bulk data. The same key pairs also support digital signatures, where the private key signs and the public key verifies.
● Examples
- 01
TLS uses RSA or ECDHE to establish a symmetric session key.
- 02
PGP/GPG encrypts an email body to the recipient's public key.
● Frequently asked questions
What is 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. It belongs to the Cryptography category of cybersecurity.
What does Asymmetric Encryption mean?
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.
How do you defend against Asymmetric Encryption?
Defences for Asymmetric Encryption typically combine technical controls and operational practices, as detailed in the full definition above.
What are other names for Asymmetric Encryption?
Common alternative names include: Public-key encryption.