SAN FRANCISCO--The crypto war of the 1990s provided a lot of important lessons for those involved, and the technologists, lawyers, and policy experts who successfully resisted government efforts to weaken encryption systems, worry that if those lessons aren’t heeded during the current debate, private and secure communications will soon be a memory.
The original push by law enforcement agencies and legislators in the United States to prevent the spread of strong encryption began nearly 30 years ago, at a time when the dominant forms of electronic communication were landlines and fax machines. The government worried that the nascent information revolution and emerging use of encryption would prevent police and intelligence agencies from being able to monitor the new channels of communication. The solution was a key escrow scheme that hinged on the use of the Clipper Chip, a chipset that would be built into voice and data communications devices and for which the government would have a key stored.
The plan failed for a number of reasons, including the discovery of a small technical flaw in the Clipper Chip scheme, and strong opposition from the technical and civil liberties communities. But the idea of weakening encryption for law enforcement access has never gone away, nor has the push for backdoors or other mechanisms to grant that access. The last few years have seen a dramatic rekindling of the crypto war, as the FBI, Congress, and other bodies in Washington have looked for ways to approach the challenge of strong default encryption on devices as well as on the network. Though the supporters of strong encryption prevailed in the 1990s, some of those involved at the time say the risk of losing this time around is quite real.
“During crypto war one, we didn’t know it was going to be necessary to number the crypto wars. The people working on encryption then were kind of visionaries and they had to have a certain amount of belief that the security of computers and data would be important any day now. We didn’t really even completely believe it ourselves,” Matt Blaze, a professor at Georgetown University Law School and technologist, said during a panel on encryption during the Enigma conference here Monday.
Blaze discovered the vulnerability in the original Clipper Chip design and said he’s concerned about the ramifications of another effort to force key escrow or a similar scheme on service providers and technology companies.
“In crypto war one, we were the ones asking for a change. In two, we’re trying to fight for the status quo. That gives us a very different dynamic. We’re in a position of strength at the moment but that could change. Computer security is not too good in 2020. It’s really kind of a mess and crypto is one of the things that works. Taking away this tool would be a disaster for the entire connected world.
“Any kind of key escrow scheme will be designed from the same kind of position of ignorance of what the future will look like that the Clipper Chip was in the ‘90s.”
“In crypto war one, we were the ones asking for a change. In two, we’re trying to fight for the status quo."
One of the major changes since that seminal debate decades ago is that the discussion now is not confined just to the government and technical experts. Anyone who has a modern smartphone or uses a commercial browser or secure messaging app has skin in the game. The security and privacy of those devices and communications rely on strong encryption and their utility would be hamstrung considerably by any plan that compromises that encryption.
There’s also the real possibility that a backdoor or key escrow scheme would introduce other vulnerabilities in the system, opening it up to exploitation in other ways. This is something technologists and cryptographers have warned about for many years, but has been minimized somewhat in the legislative community, where the answer is often, just build better technology. That mentality may be shifting, though.
“I think the policy world has come to accept that there’s real risk to any kind of exceptional access scheme,” said Daniel J. Weitzner, founding director of the MIT Internet Policy Research Initiative.
Designing cryptosystems is notoriously difficult and implementing them in a safe and usable way is no less challenging. Introducing intentional weaknesses, backdoors, or secret access points not only compromises security for users, it weakens those systems and limits their usability in the future.
“If the government wins this crypto war, I don’t know which things are going to be wrong or how they’re going to be wrong, but they will be wrong. I would argue that Clipper’s success would be a disaster not just for the reasons we thought in ‘93 but because they’d completely hobble and constrain our ability to evolve from the constraints we had at the time,” Blaze said.
“Crypto protocol design is really, really, really hard and [Clipper Chip] was designed by the NSA, which is really, really good at it. And they missed a small error.”