Breaking Kerberos

Feb 23, 1996

Abstract

In the design of the Kerberos protocol, random session keys are generated and used as part of the authentication process. Kerberos uses the sessions keys as shared secrets between clients and sercers, and as the basis of establishing the authenticity of service requests. Kerberos also creates a random key to act as the Kerberos server's secret key. The security of the whole system depends on the secrecy of these keys. However, due to the way that Kerberos chooses its random keys, these secret keys can be easily guessed in a matter of seconds with no more information than which week the key was generated.
In the Security Seminar on Friday, Steve Lodin and Bryn Dole will show the WRTV Channel 6 Wednesday night lead story on the Kerberos vulnerability and discuss how they discovered the vulnerability and exploited it.