this post was submitted on 27 Jan 2025
56 points (95.2% liked)
Privacy
516 readers
223 users here now
Protect your privacy in the digital world
Welcome! This is a community for all those who are interested in protecting their privacy.
Rules
PS: Don't be a smartass and try to game the system, we'll know if you're breaking the rules when we see it!
- Be nice and no bigotry/prejudice
- No tankies/alt-right fascists
- Stay on topic
- Don't promote proprietary software
- No crypto
- If you post news exclusive to a country please name it. ~(This isn't a bannable rule, just a recommendation!)~
Related communities
founded 2 months ago
MODERATORS
you are viewing a single comment's thread
view the rest of the comments
view the rest of the comments
So you still need to share a secret - the URL - over some other secure channel, otherwise you still risk leaking your secret data. Sure, it's easier to share a short piece of text than a large file, but this still doesn't solve the motivating problem that the tool is setting out to solve, namely:
Is it too hard to ask normal people to use asymmetric cryptography?
A web-based tool for temporary data sharing like this could make public-key crypto easy for non-technical people by doing all of the key management for the user. "Your key has been generated and stored in your browser. Share this public key with your correspondent and they can send secure messages to you."
The one sticking point is that your recipient needs to visit the site before you can send your vacation photos to them, but is it really that hard?
Creator of crypt.fyi here! Thank you for pointing out the lack of clarity in the 'why' statement. It really should state that sensitive data is shared through insecure channels in plain text. The in plain text part is key, as it leaves the contents indefinitely vulnerable.
Peoples eyes have glazed over at the mere sound of the words 'asymmetric encryption'. It's a bit out of touch of a statement to make haha. I believe these individuals still deserve more accessible tools that make them incrementally more secure and maybe it can be a gateway to even more secure/private solutions.
The URL contains the decryption key, so how do you imagine users of crypt.fyi share a URL to their recipients?
It's expected to be shared via an otherwise insecure channel (email, SMS, etc.). That is where there is a large compromise on convenience. I have a feature that I want to implement that separates the key from the URL so the URL and key can be shared via separate channels https://github.com/osbytes/crypt.fyi/issues/54
I can't get them to understand the difference between their email password and their login password.
It's been three decades now.
Even if you're using asymmetric cryptography, you still have to trust the insecure channel. If an attacker can replace the URL sent there with their own then they can have the sender encrypt the files with an attacker controlled public key rather than the legitimate one
This is the problem that digital signatures solve.
The difficulty is not with sharing the URL but with public key distribution, and that's why in PKI we have keyservers which associate public keys with identities (eg. email address), or certificate authorities that attest the association of identity and public key and establish a chain of trust.
A web app implementing this would play the role of the keyserver, and users would have some kind of userid that identifies them.
Sure, but then you've just shifted the problem up a level. Now I have to trust that the user id you provide me in the insecure channel really is you. Which means either trusting the insecure channel or trusting that the web app has confirmed who you are in some other way before giving you an ID.
We have to reject the first since we could skip all the asymmetric crypt and just send a symmetric key directly in the insecure channel.
If we're trusting the web app has confirmed your identity, we've moved from "just quickly go to this page and it'll generate you a public key" to "go to this site, upload a photo of your ID and a video of you saying that its you and whatever other verification is needed, then it'll give you a public key".
You originally wrote:
The hard part isn't them going to the site in advance, it's them establishing trust with the site that they are who they claim to be.