One of the main challenges posed by the internet has been the need to secure communications across a massive tangle of public and private networks.
Security experts agree that end-to-end communication encryption is the best means of defending users against third-party interception or breaches that could expose the potentially sensitive content.
End-to-end encryption, however, has been more of a dream than a reality, particularly given the rise of “walled gardens” led by internet giants such as Google, Facebook and Amazon. Each always maintains some form of access to their users’ communications.
A new approach to end-to-end encryption called Mathematical Mesh was quietly introduced at this year’s HOPE (Hackers of Planet Earth) conference by esteemed cryptographer Phillip Hallam-Baker, who is currently a principal scientist at Comodo and was formerly a member of the CERN team that designed the World Wide Web, among many other accomplishments.
What is threshold cryptography?
“Public key infrastructure (PKI) isn’t quite enough,” Hallam-Baker said, referring to the infrastructure for creating, distributing and storing digital certificates used in the cryptographic system that underlies the current prevailing means of end-to-end encryption. “We need to go a bit further and start applying a type of cryptography called threshold. We’re going to need a threshold key infrastructure.”
Threshold cryptography involves chopping secrets, or keys, into smaller bits so that a recipient of encrypted communications needs to possess a “threshold” level of bits to decrypt communications.
Although threshold infrastructures have been in use by the military and government since the early 1990s, the technology is slowly being made available to the public. The National Institute of Standards and Technology (NIST), for example, recently proposed a roadmap for creating standard threshold cryptographic schemes that could make their use more frequent.
Everybody spies; information is the target
Addressing internet security means grasping some fundamental facts, according to Hallam-Baker.
“First, security doesn’t depend upon geography. China isn’t your only security threat. They’re not the only country to spy; they’re not the only country that’s buying and using computers,” he said.
“Russia spies using computers, and they all have hacked servers in the US in recent months. That’s just a fact of life. And, you know what? There are even rumours that at some point, the United States might start doing the same thing.”
Another reality is that “money is the motive,” Hallam-Baker said.
“For most people, most of the time, the threat actors of concern are attackers that are looking to steal money, and that’s even the case with most Chinese espionage. Most of it is commercial espionage. And most of it is actually targeting other Chinese companies. The reason they have difficulty understanding our complaint is that's just the way they do business.”
The fact that “everybody’s spying on every else” to gain a financial upper hand raises another significant reality, which is that information is the target, Hallam-Baker said. Attackers don’t care whether they get data from a Zoom call, the most recent service criticised for not having end-to-end encryption, or from an Excel spreadsheet. “All this fuss about Zoom. They’re just the latest hole in the fence.”
The whole digital system is rife with insecurities, Hallam-Baker said. “How many emails do you send and receive every day? How many of those have confidential information? Do you encrypt your sensitive documents?
"Well, maybe you might, but if you do, chances are you encrypt them under a password and then send the password along with the file that was encrypted. [If] we just go after things piecemeal, we’re just going to be stuck in the same situation in ten years…which is nothing is particularly secure,” he warned.
Where Mathematical Mesh comes in
One thing that does work, according to Hallam-Baker, is reducing the number of trusted parties so that you only need to trust the endpoint of the communications and not every network through which the communications must pass.
“If you have to trust five people, you’re a lot better than if you have to trust 500.” Merely reducing the number of trusted parties, though, is not enough.
“It’s all about separation of roles, separation of duties so that there isn’t a single employee who can get hold of [root keys and do terrible things with them]. When we’re applying our separation of duties at the cryptographic level, we need to introduce more keys.”
Current public-key cryptography only gives two keys — one public key, and one private key. “If we want to be able to have more control, we’ve got to be able to start splitting up keys,” Hallam-Baker said. “If we’re going to make effective use of threshold cryptography, we’re going to need a threshold key infrastructure,” which is where Hallam-Baker’s Mathematical Mesh system comes into play.
That system is now available in “pre-alpha” release on Github, and Hallam-Baker says he is getting very close to being able to make a feature release, although he’s nervous about it. “Well, you know, you guys hack stuff,” he says.
Hallam-Baker says he’s looking at applications of the mesh system that provide early adopter users with real value, even if nobody else ever uses it. One example of that is an end-to-end secure password vault, which uses threshold cryptography to secure the data in the cloud but doesn’t allow the cloud to decrypt. He thinks this application will fill a gap in the enterprise market.
He wants companies to step up and test out his new system. “This is a call for help here, corporate participation. I think that we can do something that could be really special. Let’s do it.”