I'm going to give you a question and related context to help you answering thhe question
question: what's the current version of the Kerberos protocol?
context: "Kerberos is a network authentication protocol which was originally created by the Massachusetts
Institute of Technology (MIT) as a way to securely provide authentication across a potentially
hostile network. The Kerberos protocol uses strong cryptography so that both a client and server
can prove their identity without sending any unencrypted secrets over the network. Kerberos can
be described as an identity-verifying proxy system and as a trusted third-party authentication
system. After a user authenticates with Kerberos, their communications can be encrypted to assure
privacy and data integrity. The current version of the protocol is version 5, described in RFC 4120. Several free
implementations of this protocol are available, covering a wide range of operating systems." Please answer in JSON format.
user