# Principal designer of Kerberos

Source: https://startwithidentity.com/experts/clifford-neuman/
Last updated: 2026-09-20
License: content by Start with Identity. Cite the source URL.

---

## Bio

Clifford Neuman was one of the principal designers of Kerberos versions 1 through 4 at MIT's Project Athena, led the version 5 design with John Kohl, and is lead author of RFC 4120, the Kerberos V5 specification. He is at the USC Information Sciences Institute.

Profile built from public IETF and academic records.

## Where their work shows up

[Kerberos](https://startwithidentity.com/glossary/kerberos/) is the authentication protocol inside [Active Directory](https://startwithidentity.com/glossary/active-directory/), which means it authenticates a very large share of the working world every morning. Its ticket-granting design, authenticate once, then present short-lived tickets for each service, is the same shape as every token-based system that followed, including [OAuth](https://startwithidentity.com/standards/oauth-2-0/). It is also why an attack on ticket handling is an attack on everything. See [Kerberoasting](https://startwithidentity.com/techniques/kerberoasting/), [Kerberos delegation abuse](https://startwithidentity.com/techniques/kerberos-delegation-abuse/), and the [best ITDR for Active Directory](https://startwithidentity.com/rankings/best-itdr-for-active-directory/) ranking.