Nicolas Courtois is a cryptologist and code-breaker.
He is a Senior Lecturer at University College London.
At UCL we have a specialist M.Sc. programme in Information Security.
He has done his PhD thesis in cryptology at Paris 6 University.
His H-index is 36 according to Google Scholar.
Industry, Smart Cards, Payment:
For 7 years he worked as a cryptologist in a biggest secure hardware manufacturer in the world Gemalto.
He has filed 8 patents on industrial applications of cryptology, embedded security, smart cards and side-channel attacks.
Blockchain and Bitcoin Security and Privacy:
He has authored several papers on bitcoin. Here are his slides on bitcoin.
He is the author of the so called “Theory of Self-Destruction of Crypto Currencies”. He has invented developed countless ways to compute private keys in bitcoin due to bad randoms, key management, brain wallets etc, see for these slides and this paper or this. His recent works are about hiding criminal or just ordinary anonymous transactions inside the ordinary bitcoin blockchain some of which will be just totally invisible, see ICISSP 2017 / slides.
He is a highly influential code-breaker and author with more than 100 publications and more than 5800 citations. His research focuses on the security analysis of cryptographic schemes with particular focus on realistic attack scenarios where the amount of data available to the attacker is very low.
He is responsible for the cryptanalysis of many real-life ciphers used by hundreds of hundreds of millions of people every day, such as the Bluetooth cipher E0, the automobile cipher KeeLoq and the MiFare Classic Crypto-1 system which is very widely used in public transportation (e.g. Oyster Card) and building access control cards.
He has authored or co-authored 20 papers in Post-Quantum Cryptography. 19 are listed here: http://pqcrypto.org/mq.html (key words: HFE, Sflash, Quartz), and one more is listed here http://pqcrypto.org/code.html.