Adam Back is a crypto-hacker and cryptographer born in London in 1970 and is currently living in Malta. Adam Back’s hashcash proof-of-work system is used in counterspam technologies and cryptocurrency mining. Adam Back is one of the first people to work on Bitcoin and was contacted by Nakamoto in 2009 to give his thoughts on hashcashes usage in Bitcoin. Adam Back is a founder of the technology company Blockstream, which is one of the main contributors to Bitcoin Core. As Blockstream’s CEO, Adam brought the company into being a leading developer of the Lightning Network, liquid sidechains and other interesting projects. Adam’s contribution to Bitcoin and cryptography development has made him one of the main cryptocurrency experts today. He is actively doing talks on such topics as privacy, scaling and the future development of Bitcoin.