Least Authority Blog

Once again, I would like to recommend Tahoe-LAFS [0] (which anyone can install on their own on their servers or use the paid service from the creators of Tahoe-LAFS [1]). One can even store "shares" securely on Google Drive and Dropbox though it is a bit involved. [0] http://tahoe-lafs.org/ [1] https://leastauthority.com/

duplicity + s4[0], because s4 is greater than s3. [0] https://leastauthority.com/

Tahoe-LAFS[1] is a storage system that works similarly. It splits data into n fragments, of which any k fragments are enough to restore the data. This leads to a replication factor of only DATA_SIZE/k*n, while you can still lose n-k pieces without data loss. Additionally all data is encrypted, signed and optionally deduplicated. One of the authors of Tahoe-LAFS started a company that ported the whole system over to cloud storage providers.[2] It's still in alpha, but it's definitly worth a look if you want secure, encrypted storage without relying on a single cloud provider. 1: https://tahoe-lafs.org/trac/tahoe-lafs 2: https://leastauthority.com/

What's the point? Tarsnap is modestly cheap and extremely secure, and there other backup services which are equally cheap and almost as secure. Use at least 2x services always, so Tarsnap going down or bust (heaven forbid) isn't a big deal. There is never a perfect real-world solution, but risk mitigations that reduce risk at a higher levels of abstraction is how to get real, production-grade fault-tolerance the easier way than dredging up edge-case issues without offering usable alternatives. SpiderOak uses end-to-end encryption, but I wouldn't trust it completely https://spideroak.com/opendownload rsync.net is also pretty usable, but I wouldn't trust there is any in-flight or at-rest security http://www.rsync.net/ Tahoe LAFS provider https://leastauthority.com/ (it's possible to run your own Tahoe LAFS servers on cloud/colo boxes on several providers) The best-practice mitigation to allow backups on less secure providers is encrypt locally (end-to-end encryption effectively) and distribute restore keys to a decent quorum of managers/founders/supervisors. Having done offsite LTO tape vaulting and formal disaster recovery / business continuity planning at the organization level, it's a whole lot cheaper, easier and more flexible to use multiple cloud providers for most real use-cases (apart from multiple PiB datasets).

You might want to add TAHOE-lafs to the comparison. ( URL https://www.tahoe-lafs.org/trac/tahoe-lafs ) A usecase / commercial example of it's use would be LeastAuthority ( URL https://leastauthority.com/ ) If that's not enough already, CEPH could also be added. ( URL https://ceph.io/ceph-storage/ )

As you pointed out, since this is an adversarial use case, a robust cryptographic hash function is the way to go. [For a non-cryptographic Hash function, SeaHash [1] would be the best choice, which is violently fast!] BLAKE2b would have been the perfect choice given the adversarial nature, as it much secure and faster than MD5. [2] MD5 is so broken, it's really poor choice for any use case - cryptographic (fundamentally broken) or not (fundamentally slow). [1] http://ticki.github.io/blog/seahash-explained/ [2] https://leastauthority.com/blog/BLAKE2-harder-better-faster-stronger-t…

I'm curious what the pricing will be when this is opened up to the public. Some years ago when I compared encrypted online storage, I found Least Authority to be quite expensive. It still seems to be ($25 a month). [1] [1]: https://leastauthority.com/

In Tahoe-LAFS, it is actually a proven truth that, up to the level of cryptographic unguessability, server operators cannot read stored files without knowing the client-side key. If you can prove otherwise, then you can earn a spot in their hall of fame: https://tahoe-lafs.org/hacktahoelafs/ Tahoe-LAFS providers like Least Authority [1] and Matador Cloud [2] pride themselves on not being able to access your data. [1] https://leastauthority.com/ [2] https://matador.cloud/

You can't be serious. It's using libsodium in one part of the code, so therefore ALL cryptography uses libsodium? You do know that Bitcoin has already switched most of the secp256k1 stuff away from OpenSSL and to libsecp256k1, and ZCash will follow suit? But more importantly than that it uses libsnark for the actual clever bits, which has already been critically broken[1] precisely because it is so new and poorly tested. Even the cryptography in ZeroCash/ZeroCoin is too new to be trusted with a financial system. That is not alarmist, that is practical. Relying on old, established cryptography is precisely why Bitcoin hasn't been trivially broken, and the zk-snarks cryptography will need to go through the same peer-review and refinement process over the next decade or two. [1] https://leastauthority.com/blog/a_bug_in_libsnark.html

If this is interesting, recommend looking at Tahoe-LAFS too: https://www.tahoe-lafs.org/trac/tahoe-lafs (And https://leastauthority.com/how_it_works )

The front-end is already there : https://tahoe-lafs.org/trac/tahoe-lafs. Backends are currently being developed (https://github.com/mk-fg/tahoe-lafs-public-clouds), and there will even be a public offering from the very same guys (https://leastauthority.com/)

Have you considered S4 by Least Authority? https://leastauthority.com

this is a political problem, but can also be addressed as an engineering problem: https://leastauthority.com/ and https://www.tahoe-lafs.org/

Interesting, but not really what I'm talking about. On https://leastauthority.com/ there's mention of development of a "Magic Folder" tool that seems to do more of the sort of thing I'm looking at.

SHA1 is long past its expiry date. NIST has been recommending to move away from it since 2010, and it outright banned it last year. And when the NSA-influenced NIST recommends something, you know you should be doing it at least 3 years earlier. Someone like NSA or even a drug cartel can pretty easily break it now. This is a 2 year old article: https://www.schneier.com/blog/archives/2012/10/when_will_we_se.html If you're worried about the performance overhead of SHA2, just use Blake2, which is actually faster than SHA1 and even MD5: https://leastauthority.com/blog/BLAKE2-harder-better-faster-stronger-t… http://bench.cr.yp.to/results-sha3.html#amd64-titan0 https://blake2.net/

And if you don't want some govt to take down a single provider like what happened with Lavabit email vis-a-vis backup, go with a distribute (multi-provider) solution like Tahoe LAFS https://leastauthority.com/ The proxy is run locally and all encryption happens locally, so it's end-to-end encrypted.

I suspect this as well - the part where they talk about "even if half of the remaining nodes disappeared" makes me think that a Tahoe (or tahoe style) technology is behind this. Interestingly, the Tahoe people have their own product to offer: https://leastauthority.com/ ... although I have no idea what state of production that is in ...

So how do you differentiate your service from Least Authority [0]? [0] https://leastauthority.com/

Tahoe-LAFS-on-s3 from Least Authority Enterprises https://leastauthority.com Bonus: one user, 'sickness', showed how to replicate your encrypted data across Dropbox, gdrive, etc. http://www.sickness.it/crazycloudexperiment.txt

One of the Cryptodog devs here - no Chrome 0days in our possession (yet). The code's all on Github: https://github.com/Cryptodog/cryptodog. No signed extensions or apps yet, but you can clone and run locally for testing purposes, or use the hosted client linked there. So far, we've been focusing on refactoring, fixing surface bugs, and making the UI more attractive and intuitive -- none of the underlying cryptography has been touched. It also performs slightly faster than stock Cryptocat. Since Nadim took down his XMPP server, we've had to create our own, but the backend is identical to his setup. Of course, Cryptodog is by no means the best solution for E2E chat, just as Cryptocat wasn't. The best we can hope to achieve without a complete codebase overhaul is a reasonable level of security (https://leastauthority.com/static/publications/LeastAuthority-Cryptoca… However, it's still a fairly usable app that can afford casual users protection against basic threats, like corporate data mining. Issue postings, pull requests, and other miscellaneous contributions are all welcome.

tahoe-lafs, https://tahoe-lafs.org/trac/tahoe-lafs , is "an open source, secure, decentralized, fault-tolerant, peer-to-peer distributed data store and distributed file system." It has the server-level RAID you desire. The FAQ states: ``You know how with RAID-5 you can lose any one drive and still recover? And there is also something called RAID-6 where you can lose any two drives and still recover. Erasure coding is the generalization of this pattern: you get to configure how many drives you could lose and still recover. You can choose how many drives (actually storage servers) will be used in total, from 1 to 256, and how many storage servers are required to recover all the data, from 1 to however many storage servers there are. We call the number of total servers N and the number required K, and we write the parameters as "K-of-N".'' It's a very active open source project, with full-time contributors (I think?), funded by their commercial arm, https://leastauthority.com/ .

There is Destiny https://leastauthority.com/community-matters/destiny/. Although there hasn't been much activity lately.

Least Authority is actually a German company now (although it was started in the US): https://leastauthority.com/about-us/

I worked on the OTF-funded security audit of Cryptocat. (The report: https://leastauthority.com/static/publications/LeastAuthority-Cryptoca… While I wasn't involved in arranging the work, my vague memory is that a publically-disclosed audit was a condition of the funding -- I think the OTF had that policy in general. (It's been a few years, and I haven't kept up.) Even the author of CryptoCat now thinks you should not use CryptoCat, but I would not rush to assume ill of the OTF funding it back then.

Nice BLAKE2 article from HN in March, 2014 https://leastauthority.com/blog/BLAKE2-harder-better-faster-stronger-t…

My startup company is joining "Reset The Net" by deploying an upgrade to our encrypted cloud storage product and cutting the price in half: https://leastauthority.com/blog/

Least Authority's blog post about the audit: https://leastauthority.com/blog/least_authority_performs_security_audi…

Yup, here are a number of articles on the subject https://leastauthority.com/blog/debunking-the-nothing-to-hide-rhetoric… https://www.techrepublic.com/blog/it-security/why-nothing-to-hide-misr… http://www.msnbc.com/msnbc/surveillance-you-may-have-nothing-hide https://www.wired.com/2013/06/why-i-have-nothing-to-hide-is-the-wrong-… https://www.zdnet.com/article/privacy-is-innately-flawed-nothing-to-hi… https://mashable.com/2013/06/13/julian-sanchez-nsa/ https://www.techdirt.com/articles/20130613/12180423457/if-youve-got-no… https://www.washingtonexaminer.com/tim-carney-even-law-abiding-people-… https://www.chronicle.com/article/Why-Privacy-Matters-Even-if/127461/ https://uproxx.com/technology/prism-why-you-should-care-even-if-you-ha… https://reason.com/2013/06/12/three-reasons-the-nothing-to-hide-crowd/ https://www.schneier.com/blog/archives/2006/05/the_value_of_pr.html