Elizebeth Smith Friedman (August 26, 1892 – October 31, 1980) was a cryptanalyst and author, and a pioneer in U.S. cryptography. She has been dubbed "America's first female cryptanalyst".

She was the wife of William Frederick Friedman, a notable cryptographer credited with numerous contributions to cryptology. She, however, enjoyed many successes in her own right, and it was Elizebeth who first introduced her husband to the field.

In 1962 she described single-substitution alphabet decipherings of the Voynich Manuscript as "doomed to utter frustration".(Wikipedia page on the VM [1] refers).

The couple were also involved in cryptographical analysis of the Shakespeare corpus, and disproving the contention that Francis Bacon wrote the plays.

There is a fuller biography on Wikipedia at [2]; also here [3] and here National Security Agency, and many other articles.

The Friedmans donated their archives to the George C. Marshall Foundation.