Daniel Chechik is a senior security researcher at Trustwave's SpiderLabs. He has spoken at the BlackHat conference, holds CEH and CCSE certificates and has a patent pending for 'Detecting Malware Communication on an Infected Computing Device'.
He was the one who discovered the Bitcoin Maleability vulnerability
https://www.trustwave.com/Resources/SpiderLabs-Blog/Bitcoin-Transaction-...
https://twitter.com/danielchechik
https://ruxcon.org.au/speakers/#Daniel Chechik
http://www.rsaconference.com/speakers/daniel-chechik