From “The Crypto-Currency” by Joshua Davis, The New Yorker, October 10, 2011:
Dan Kaminsky, a leading Internet-security researcher, investigated Bitcoin’s code — roughly 31,000 lines at the time.
“When I first looked at the code, I was sure I was going to be able to break it,” Kaminsky said.
“The way the whole thing was formatted was insane. Only the most paranoid, painstaking coder in the world could avoid making mistakes.”
He quickly identified nine ways to compromise the system and began attacking the code. But when he found the right spot, there was a message waiting for him: “Attack Removed,” it said. The same thing happened over and over, infuriating Kaminsky.
“I came up with beautiful bugs,” he said. “But every time I went after the code there was a line that addressed the problem.”
“He’s a world-class programmer, with a deep understanding of the C++ programming language,” Kaminsky said of Bitcoin’s creator. “He understands economics, cryptography, and peer-to-peer networking.”
“Either there’s a team of people who worked on this,” he said, “or this guy is a genius.”
[Dan Kaminsky also presented his Bitcoin analysis at Black Hat USA 2011 in Las Vegas. In 2013, he told CoinDesk: “The core technology actually works, and has continued to work, to a degree not everyone predicted.” Kaminsky was famous for discovering a critical DNS vulnerability in 2008. He passed away on April 23, 2021.]