Pieter Wuille is the co-founder of Blockstream and a top Bitcoin core developer. Wuille is best known for developing committed libraries Segregated Witness, libsecp256k1 and BIP (bitcoin proposal) 66

Born in Belgium, Wuille discovered Bitcoin in 2010. He was working at Google in Switzerland when he stumbled across the project in a chat channel dedicated to the programming language Haskell. In February 2011, he noticed a post from noted cryptographer Hal Finney in Bitcointalk, a Bitcoin forum established by Satoshi Nakamoto, that hoped to speed up signature verification in Bitcoin. This became Wuille’s first Bitcoin project. 

Wuille’s first commit, BIP32, came in February of 2011 and was regarding “hierarchical deterministic wallets.” This standard made storing and recovering keys easier when interacting with a bitcoin wallet. It allowed for the generation of a human-readable phrase as a seed to recover keys even if someone lost their alpha-numeric private key.

Wuille’s BIP 0141, Segregated Witness (SegWit), is the code he is best known for implementing. The code changes the way data is stored in blocks, and enables the development of “layer two” projects, such as scaling solutions like the Lightning Network. The library was notably criticized by Bitcoin Cash advocate Roger Ver as a solution that was “too little, and too late.”

As of 2019, Wuille has been focused on Schnorr signatures, an alternative to ECDSA signatures intended to allow the network to process more transactions and increase the privacy of its payments. The cryptographic signature closely related to ECDSA was originally patented by Claus Schnorr, but the patent expired in 2008 allowing its open use.