"bitcoin security" entries
The O'Reilly Radar Podcast: Mike Belshe on making bitcoin secure and easy enough for the mainstream.
In this week’s O’Reilly Radar Podcast episode, I caught up with Mike Belshe, CTO and co-founder of BitGo, a company that has developed a multi-signature wallet that works with bitcoin. Belshe talks about about the security issues addressed by multi-signature wallets, how the technology works, and the challenges in bringing cryptocurrencies mainstream. We also talk about his journey into the bitcoin world, and he chimes in on what money will look like in the future. Belshe will address the topics of security and multi-signature technology at our upcoming Bitcoin & the Blockchain Radar Summit on January 27, 2015, in San Francisco — for more on the program and registration information, visit our Bitcoin & the Blockchain website.
Multi-signature technology is exactly what it sounds like: instead of authorizing bitcoin transactions with a single signature and a single key (the traditional method), it requires multiple signatures and/or multiple machines — and any combination thereof. The concept initially was developed as a solution for malware. Belshe explains:
“I’m fully convinced that the folks who have been writing various types of malware that steal fairly trivial identity information — logins and passwords that they sell super cheap — they are retooling their viruses, their scanners, their key loggers for bitcoin. We’ve seen evidence of that over the last 12 months, for sure. Without multi-signature, if you do a bitcoin transaction on a machine that’s got any of this bad stuff on it, you’re pretty much toast. Multi-signature was my hope to fix that. What we do is make one signature happen on the server machine, one signature happen on the client machine, your home machine. That way the attacker has to actually compromise two totally different systems in order to steal your bitcoin. That’s what multi-signature is about.”
The core principle in bitcoin is decentralization, and it has important implications for security.
Editor’s note: this is an excerpt from Chapter 10 of our recently released book Mastering Bitcoin, by Andreas Antonopoulos. You can read the full chapter here. Antonopoulos will be speaking at our upcoming event Bitcoin & the Blockchain, January 27, 2015, in San Francisco. Find out more about the event and reserve your spot here.Securing bitcoin is challenging because bitcoin is not an abstract reference to value, like a balance in a bank account. Bitcoin is very much like digital cash or gold. You’ve probably heard the expression “Possession is nine tenths of the law.” Well, in bitcoin, possession is ten tenths of the law. Possession of the keys to unlock the bitcoin, is equivalent to possession of cash or a chunk of precious metal. You can lose it, misplace it, have it stolen, or accidentally give the wrong amount to someone. In every one of those cases, end users would have no recourse, just as if they dropped cash on a public sidewalk.
However, bitcoin has capabilities that cash, gold, and bank accounts do not. A bitcoin wallet, containing your keys, can be backed up like any file. It can be stored in multiple copies, even printed on paper for hardcopy backup. You can’t “backup” cash, gold, or bank accounts. Bitcoin is different enough from anything that has come before that we need to think about bitcoin security in a novel way too.
The core principle in bitcoin is decentralization and it has important implications for security. A centralized model, such as a traditional bank or payment network, depends on access control and vetting to keep bad actors out of the system. By comparison, a decentralized system like bitcoin pushes the responsibility and control to the end users. Because security of the network is based on Proof-Of-Work, not access control, the network can be open and no encryption is required for bitcoin traffic. Read more…