Public key cryptography uses a pair of keys to encrypt and decrypt data to protect it against unauthorized access or use. ... This key is used to encrypt the message, and to send it to the recipient. When the message arrives, the recipient decrypts it using a private key, to which no one else has access.

What is a public key used for?

In cryptography, a public key is a large numerical value that is used to encrypt data. The key can be generated by a software program, but more often, it is provided by a trusted, designated authority and made available to everyone through a publicly accessible repository or directory.

What is the principle of public key cryptography?

Public key cryptosystem is one which involves two separate keys for encryption and decryption. Each user participating in the communication has to generate two keys, one is to be kept secret (private key) and one is to make public (public key). Public key cryptosystem can achieve both confidentiality and authenticity.