Proton Mail, the leading privacy-focused email service, is making its first foray into blockchain technology with Key Transparency, which will allow users to verify email addresses. From a report: In an interview with Fortune, CEO and founder Andy Yen made clear that although the new feature uses blockchain, the key technology behind crypto, Key Transparency isn’t “some sketchy cryptocurrency” linked to an “exit scam.” A student of cryptography, Yen added that the new feature is “blockchain in a very pure form,” and it allows the platform to solve the thorny issue of ensuring that every email address actually belongs to the person who’s claiming it.
Proton Mail uses end-to-end encryption, a secure form of communication that ensures only the intended recipient can read the information. Senders encrypt an email using their intended recipient’s public key – a long string of letters and numbers – which the recipient can then decrypt with their own private key. The issue, Yen said, is ensuring that the public key actually belongs to the intended recipient. “Maybe it’s the NSA that has created a fake public key linked to you, and I’m somehow tricked into encrypting data with that public key,” he told Fortune. In the security space, the tactic is known as a “man-in-the-middle attack,” like a postal worker opening your bank statement to get your social security number and then resealing the envelope.
Blockchains are an immutable ledger, meaning any data initially entered onto them can’t be altered. Yen realized that putting users’ public keys on a blockchain would create a record ensuring those keys actually belonged to them – and would be cross-referenced whenever other users send emails. “In order for the verification to be trusted, it needs to be public, and it needs to be unchanging,” Yen said.
Curious if anyone here would use a feature like this? It sounds neat but I don’t think I’m going to be needing a feature like this on a day-to-day basis, though I could see use cases for folks handling sensitive information.
What do you think the problem even is? It sounds like you just don’t understand why someone would want to use public key cryptography to begin with.
I understand how public-private keys work, and I understand why you’d want one. I just think this implementation of a register is bad. Not from a security risk, from a use case point of view; it’s for all intent and purposes an email which if ever compromised is forever compromised and non reusable. It’s an email that’s unrecoverable so not usable in many companies.
I’m sure there are other reasons to not like the idea, but that’s what I can think off the top of my head.
It doesn’t sound like you understand why someone would want to do email with public key cryptography, it sounds like rather you do not like the idea of doing email with public key cryptography. Being unrecoverable is just the tradeoff there. Again, what do you think the problem described even is? For reference,
I think if you actually acknowledge the problem of trust for propagating public keys as a real one that is worth being solved, it would be hard to argue that blockchain is a bad fit for that problem, because it is not. Trustless, verifiable propagation of data is one of the things it actually offers unique benefits for.
It might be useful to start by considering the idea itself and what it is saying, instead of looking for arguments to make against it.
You’re not adding anything that wasn’t argued towards before. Soon or later, you have to trust something. There are ways to transfer keys by other means which you can use to corroborate.
The tradeoffs of this idea are just not worth it for 99% of the people.
What are the tradeoffs, assuming an email encryption scheme based on self custodied private keys and publicly published public keys? I don’t see any major disadvantages to using blockchain for this, and significant advantages. It’s a big deal if no one can selectively remove/conceal previously published info. If associating a key with an email, and someone is trying to impersonate you, you’ll know it, it’s not going to be hidden from you and specifically shown to someone else. It just makes sense to do it that way. Yes, you have to trust something at some point, but this is a way to minimize how much trust you have to give.
It’s not recoverable and permanently compromised if ever it is.
Also, even if someone was trying to impersonate you, you wouldn’t know it unless the recipient told you (which could also be done today with DMARCs, albeit at a domain level not an email level)