Usage of asymmetric key algorithms

Security applications (such as SSH, SSL, and PKI) use the asymmetric key algorithms for the following purposes:

• Encryption and decryption—Any public key receiver can use the public key to encrypt information, but only the private key owner can decrypt the information.

• Digital signature—The key owner uses the private key to digitally sign information to be sent. The receiver decrypts the information with the sender's public key to verify information authenticity.

RSA, DSA, and ECDSA can all perform digital signature, but only RSA can perform encryption and decryption.