Wei Dai (Chinese: 戴伟[1]) is a computer engineer known for contributions to cryptography and cryptocurrencies. He developed the Crypto++ cryptographic library, created the b-money cryptocurrency system, and co-proposed the VMAC message authentication algorithm.
Dai graduated from the University of Washington[when?] with a degree in computer science[2] and is described as an "intensely private computer engineer".[3] Wei Dai was member of the Cypherpunks, Extropians, and SL4 mailing lists in the 1990s. On SL4 he exchanged with people such as Eliezer Yudkowsky, Robin Hanson, Nick Bostrom, Aubrey de Grey, Anders Sandberg, Eric Drexler, David Pearce, Hal Finney, and others in the nascent "rationalist" community.[4]
Dai has made several contributions to the field of cryptography and has identified critical Cipher Block Chaining (CBC) vulnerabilities affecting SSH2[5] and the browser exploit against SSL/TLS known as BEAST (Browser Exploit Against SSL/TLS).[6][7]
In June 2015 Dai stepped away from the Crypto++ project[clarification needed] to work on other projects. Crypto++ is now maintained by the Crypto++ community.[8]
VMAC is a block cipher-based message authentication code (MAC) algorithm using a universal hash proposed by Ted Krovetz and Wei Dai in April 2007. The algorithm was designed for high performance backed by a formal analysis.[9][non-primary source needed]
In 1998, Dai helped to spark interest in cryptocurrencies[10] with the publication of "b-money, an anonymous, distributed electronic cash system".[11][12] In the paper, Dai outlines the basic properties of all modern day cryptocurrency systems: "...a scheme for a group of untraceable digital pseudonyms to pay each other with money and to enforce contracts amongst themselves without outside help".[13][14]