Which key is kept secret in asymmetric encryption?

In asymmetric encryption, one of the core components is the use of a key pair consisting of a public key and a private key. The private key is crucial because it is kept secret and is used to decrypt messages that have been encrypted with the corresponding public key. This means that while anyone can access and use the public key to encrypt messages, only the holder of the private key can decrypt those messages, ensuring confidentiality.

The security model of asymmetric encryption relies on the private key remaining confidential to protect the integrity and privacy of the messages exchanged. If the private key were to be disclosed, anyone could decrypt messages intended for the key holder, compromising the security of the communication. Therefore, the private key is always safeguarded and not shared, contrasting with the public key, which is intended to be shared widely.