Joan Clarke, English cryptanalyst and numismatist (born 1917)

Joan Elisabeth Lowther Murray, MBE was an English cryptanalyst and numismatist who worked as a code-breaker at Bletchley Park during the Second World War. Although she did not personally seek the spotlight, her role in the Enigma project that decrypted the German secret communications earned her awards and citations, such as appointment as a Member of the Order of the British Empire (MBE), in 1946.

Cryptanalysis refers to the process of analyzing information systems in order to understand hidden aspects of the systems. Cryptanalysis is used to breach cryptographic security systems and gain access to the contents of encrypted messages, even if the cryptographic key is unknown.

A numismatist is a specialist, researcher, and/or well-informed collector of numismatics/coins. Numismatists can include collectors, specialist dealers, and scholar-researchers who use coins in object-based research. Although use of the term numismatics was first recorded in English in 1799, people had been collecting and studying coins long before then all over the world.