Dan Shumow

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Dan Shumow is a cryptographer working at Microsoft Research.

At the CRYPTO 2007 conference rump session, Dan Shumow and Niels Ferguson presented an informal paper describing a kleptographic backdoor in the NIST specified Dual_EC_DRBG cryptographically secure pseudorandom number generator.{{cite web|url=http://rump2007.cr.yp.to/15-shumow.pdf |title=On the Possibility of a Back Door in the NIST SP800-90 Dual Ec Prng |first1=Dan |last1=Shumow |first2=Niels |last2=Ferguson }} The backdoor was confirmed to be real in 2013 as part of the Edward Snowden leaks.

Dan Shumow co-authored an algorithm for detecting SHA-1 collisions with Marc Stevens, prior to the demonstration of a SHA-1 collision.{{Cite web|url=http://shattered.io/|title=SHAttered|website=shattered.io}}

In 2024, Dan Shumow co-authored a paper{{cite web |title=blastradius attack |url=https://www.blastradius.fail/}} described an attack against the RADIUS protocol, allowing a man-in-the-middle able between client and server to forge a valid protocol accept message in response to a failed authentication request.