4 ms·

Is this different or do they do the exact same thing? https://github.com/paritytech/banana_split https://github.com/paritytech/banana_split

cyphar 3y ago
Paperback predates that tool (though to be fair, it still has to have a nice GUI interface made for it, and to be honest I have been working on it off more than on). Also, I suspect they don't support reconstructing lost shards or adding new shards after sharing (this is trivial to do from the maths but very few tools seem to have this pretty important feature). I talk about this in the LCA talk I did on paperback[1]. There are also some attacks against SSS that require workarounds and it seems to me they don't have any protections against them (in paperback's case, there are several measures to defend against forged shards -- one of which is that all shards are signed with an Ed25519 key whose private half is in the sharded secret). That being said, the underlying cryptography is quite old and there aren't too many new ways you can spin it -- the goal of paperback was to make it possible for paper backups to be done in a way that non-technical folks can understand the properties. How well it currently lives up to that goal is a different question, of course. I mainly wrote paperback because the existing SSS systems I could find at the time were all either very primitive, had serious security issues (I found two or three serious cryptographic vulnerabilities in the handful of existing tools at the time -- and I'm not a cryptographer by any stretch of the imagination), or were not usable as a paper backups system. There are more around now and it's possible I wouldn't have bothered with paperback if they'd existed back then. [1]: https://www.youtube.com/watch?v=GI9rKdM9rB8&t=1368 https://www.youtube.com/watch?v=GI9rKdM9rB8&t=1368
elliotec 3y ago
It’s the same but with a framework to share between people rather than just hiding pieces of paper around the world.

cyphar 3y ago

Paperback predates that tool (though to be fair, it still has to have a nice GUI interface made for it, and to be honest I have been working on it off more than on). Also, I suspect they don't support reconstructing lost shards or adding new shards after sharing (this is trivial to do from the maths but very few tools seem to have this pretty important feature). I talk about this in the LCA talk I did on paperback[1]. There are also some attacks against SSS that require workarounds and it seems to me they don't have any protections against them (in paperback's case, there are several measures to defend against forged shards -- one of which is that all shards are signed with an Ed25519 key whose private half is in the sharded secret). That being said, the underlying cryptography is quite old and there aren't too many new ways you can spin it -- the goal of paperback was to make it possible for paper backups to be done in a way that non-technical folks can understand the properties. How well it currently lives up to that goal is a different question, of course. I mainly wrote paperback because the existing SSS systems I could find at the time were all either very primitive, had serious security issues (I found two or three serious cryptographic vulnerabilities in the handful of existing tools at the time -- and I'm not a cryptographer by any stretch of the imagination), or were not usable as a paper backups system. There are more around now and it's possible I wouldn't have bothered with paperback if they'd existed back then. [1]: https://www.youtube.com/watch?v=GI9rKdM9rB8&t=1368 https://www.youtube.com/watch?v=GI9rKdM9rB8&t=1368

elliotec 3y ago

It’s the same but with a framework to share between people rather than just hiding pieces of paper around the world.