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Cryptpad: Zero Knowledge, Collaborative Real Time Editing

beta.cryptpad.fr

41–50 of 54 posts

Re: Cryptpad: Zero Knowledge, Collaborative Real Time Editing

#41
post #30

I have often seen claims that doing any kind of crypto in (browser) javascript is dangerous. Does this fall into that trap? How can I safely share the URL to someone without already using an established encrypted communication method? Is the encryption key stored in my browser history?

The reason crypto in the browser is dangerous is because the crypto algorithms come from the server (they aren't built into the browser) so you have to verify them every time you go to the site to know they're doing everything properly. They could easily change them to no ops for you at the request of the NSA or whatever and you wouldn't know. So on the basis of that, I don't think this project avoids that problem

iOS silently installs updates too all apps from the App Store.

There is no meaningful distinction between Javascript being served from the server and an App being served from the App Store.

Re: Cryptpad: Zero Knowledge, Collaborative Real Time Editing

#42
post #41
post #30

Earlier quoted context omitted.

The reason crypto in the browser is dangerous is because the crypto algorithms come from the server (they aren't built into the browser) so you have to verify them every time you go to the site to know they're doing everything properly. They could easily change them to no ops for you at the request of the NSA or whatever and you wouldn't know. So on the basis of that, I don't think this project avoids that problem

iOS silently installs updates too all apps from the App Store. There is no meaningful distinction between Javascript being served from the server and an App being served from the App Store.

Yes. Yes they do, and I agree – there is no meaningful distinction.

https://www.gnu.org/proprietary/proprietary-back-doors.en.ht...

Re: Cryptpad: Zero Knowledge, Collaborative Real Time Editing

#43

Why do people insist on using the term zero knowledge for simple semantically secure encryption? Zero knowledge has a very specific meaning inside cryptography. Encrypting something does not make it "zero knowledge".

This is a fair question. I'm somewhat to blame for contributing to it over the last 10 years via SpiderOak. There are very good reasons though, and it's probably time I made a post about it.

Re: Cryptpad: Zero Knowledge, Collaborative Real Time Editing

#45

Earlier quoted context omitted.

Note that in the field of cryptography, the term zero knowledge refers to zero knowledge proofs, which predate that company by over 13 years.

I don't dispute that fact. But there is precedent for the use of the term in privacy-respecting services, so we shouldn't be surprised when we encounter it. After ZKS shut down, the term continued to be used by hosting and communications services to explain their value proposition in a simple way. Having said that, I agree with the point that nowadays this usage may be unhelpful in promoting privacy-respecting servic…

Then that is a pretty poor precedent, however I've not seen people (who actually understand cryptography or security) reference "zero knowledge" as the fact that the provider can't access your data.

Re: Cryptpad: Zero Knowledge, Collaborative Real Time Editing

#46

Why do people insist on using the term zero knowledge for simple semantically secure encryption? Zero knowledge has a very specific meaning inside cryptography. Encrypting something does not make it "zero knowledge".

> Why do people insist on using the term zero knowledge for simple semantically secure encryption? Note that in the domain of privacy-enhancing technologies the term "zero-knowledge" does not refer to "semantically secure encryption". Instead it is used to mean that a service provider does not have access to user data, and that this claim can be proven cryptographically. The use of the term zero-knowledge to promote…

Alternatively, based on my assumption that English is only a second language for the authors[1] I also think it might just be a cultural/language issue. Being a non-native english speaker myself, I frequently find myself differing in word usages with the native speakers. And there is probably no formalized naming convention (like scientific names in biology), it's what's all in people's heads. What Fowler said about naming being hard is probably very true [2].

[1]: https://github.com/xwiki-labs/cryptpad/graphs/contributors [2]: http://martinfowler.com/bliki/TwoHardThings.html

Re: Cryptpad: Zero Knowledge, Collaborative Real Time Editing

#47
post #2

This is a cool implementation of this idea. Proof of work is probably an acceptable solution for proof of concept but anonymous consensus isn't needed for for collaborative document editing. I'm still thinking if this use cases needs timestamping or atomic broadcast.If timestamping is sufficient, Google's new roughtime protocol would do the job well. Otherwise you need a proper atomic broadcast algorithim like RAFT,…

There doesn't appear to be any mining, proof-of-work, anonymous consensus, or fault-tolerant consensus of any kind in this project. I think they just threw the phrase "Nakamoto blockchain" in there as inspiration, really they are just using hashchains from 1999.

Re: Cryptpad: Zero Knowledge, Collaborative Real Time Editing

#48
post #2

This is a cool implementation of this idea. Proof of work is probably an acceptable solution for proof of concept but anonymous consensus isn't needed for for collaborative document editing. I'm still thinking if this use cases needs timestamping or atomic broadcast.If timestamping is sufficient, Google's new roughtime protocol would do the job well. Otherwise you need a proper atomic broadcast algorithim like RAFT,…

There doesn't appear to be any mining, proof-of-work, anonymous consensus, or fault-tolerant consensus of any kind in this project. I think they just threw the phrase "Nakamoto blockchain" in there as inspiration, really they are just using hashchains from 1999.

That's disappointing :-(

Re: Cryptpad: Zero Knowledge, Collaborative Real Time Editing

#49
post #2

This is a cool implementation of this idea. Proof of work is probably an acceptable solution for proof of concept but anonymous consensus isn't needed for for collaborative document editing. I'm still thinking if this use cases needs timestamping or atomic broadcast.If timestamping is sufficient, Google's new roughtime protocol would do the job well. Otherwise you need a proper atomic broadcast algorithim like RAFT,…

There doesn't appear to be any mining, proof-of-work, anonymous consensus, or fault-tolerant consensus of any kind in this project. I think they just threw the phrase "Nakamoto blockchain" in there as inspiration, really they are just using hashchains from 1999.

I would very much like to see someone built out the transcript validation application of atomic broadcast rather than a distributed ledger version.

Re: Cryptpad: Zero Knowledge, Collaborative Real Time Editing

#50

Earlier quoted context omitted.

File size and date sent is probably only useful if someone is specifically targeting you, and it's virtually guaranteed that the only person who wound target someone specifically and also be able to make use of that data is a government agency. In that case they'd be able to monitor your data at an ISP level anyway, making it moot. It doesn't look like Spideroak takes bitcoin payments anyway, making this even further…

Useful or not, I consider the boldface statement > we know nothing about the encrypted data you store on our servers misleading, since they do know some things about the encrypted data.

I strongly support SpiderOak but I agree with you. Even if they don't keep logs of that stuff, they could or could be ordered to do so. They obviously think the "ordered to do so" part is a real threat because they dissuade used from logging in through the website.
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