He developed the Crypto++ cryptographic library, created the b-money cryptocurrency system, and co-proposed the VMAC message authentication algorithm.
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 a nascent rationalist community.
[13][14] 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".
[15][16] 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.
[23]There has been much speculation as to the identity of Satoshi Nakamoto, with suspects including Wei Dai himself, Nick Szabo, and Hal Finney, all of whom have denied the putative identification.