# Co-author of the Needham-Schroeder protocol

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

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## Bio

Michael D. Schroeder co-authored two of the foundational papers in this field within three years of each other: the 1975 design-principles paper with Jerome Saltzer at MIT, and the 1978 authentication paper with Roger Needham at Xerox PARC.

Profile built from public academic and publication records.

## Where their work shows up

The 1978 paper's symmetric-key protocol is the direct ancestor of [Kerberos](https://startwithidentity.com/glossary/kerberos/), which means it is the ancestor of how Windows domains authenticate to this day. Its public-key variant was later shown to be flawed and fixed, which established something equally important: authentication protocols need formal analysis, not just careful reading. That lesson runs straight through to the formal work on [OAuth](https://startwithidentity.com/standards/oauth-2-0/) decades later. See [Kerberoasting](https://startwithidentity.com/techniques/kerberoasting/) and [Kerberos delegation abuse](https://startwithidentity.com/techniques/kerberos-delegation-abuse/) for what the protocol's descendants look like under attack.