A session key is a temporary cryptographic key used to encrypt communication between two systems for a single session. Session keys are typically symmetric keys generated during secure key exchange processes such as TLS handshakes.

They provide confidentiality and efficiency because symmetric encryption is much faster than asymmetric encryption. Once the session ends, the key is discarded, limiting exposure even if the key is later compromised.

Public keys are used for key exchange and authentication, not bulk data encryption. “Temporary key” and “section key” are not standard cryptographic terms.

Session keys are fundamental to secure network communications and are recommended by all modern cryptographic standards due to their performance and security benefits.