TLS-PSK


Transport Layer Security pre-shared key ciphersuites is a set of cryptographic protocols that provide secure communication based on pre-shared keys. These pre-shared keys are symmetric keys shared in advance among the communicating parties.
There are several cipher suites: The first set of ciphersuites use only symmetric key operations for authentication. The second set use a Diffie-Hellman key exchange authenticated with a pre-shared key. The third set combine public key authentication of the server with pre-shared key authentication of the client.
Usually, Transport Layer Security uses public key certificates or Kerberos for authentication. TLS-PSK uses symmetric keys, shared in advance among the communicating parties, to establish a TLS connection. There are several reasons to use PSKs: