What the CIA WikiLeaks Dump Tells Us: Encryption Works • Hacker News Board

Re: What the CIA WikiLeaks Dump Tells Us: Encryption Works

#231

Post by tialaramex » Sun, Mar 12, 2017, 9:23 AM UTC

catshirt wrote: post #97

andai wrote: post #67

I don't see any mention of quantum computers in here so I thought I'd mention: the NSA themselves are concerned that quantum computing will be a great threat to encryption in the near future. Keep in mind that the NSA and god knows who else are storing encrypted communications to break them later. Quantum computing will defeat RSA, DH, ECC, asymmetric crypto, but it will only weaken symmetric crypto (eg. AES) by a fa…

> the NSA themselves are concerned that quantum computing will be a great threat to encryption in the near future. pardon my ignorance. but, isn't this an inevitability? not just a possibility?

No. For two reasons, a general reason and a specific reason.

Firstly, quantum computing at scale _might_ be possible in our universe but it might not. One of the spookiest things that might still be true would be a thing called finite non-local hidden state. In this scenario the whole universe has some sort of hidden state, a bit like the seed value of a Minecraft world. Quantum computing in a universe with finite non-local hidden state just weirdly "doesn't work" when you scale it up, because it's basically using the universe's hidden state as magic working storage, and that runs out. Simulation nuts would tell you finite non-local hidden state makes it pretty clear we're in a simulation, but then they would say say that...

Secondly it says "near future". We have every reason to believe there will be serious obstacles to scaling up quantum computing. Somebody else gave the example of Babbage's engine. Just because we can conceive of fusion power generation doesn't mean it's going to happen next week.

Or at all. At the start of the 20th century some mathematicians thought all of mathematics could be formulated as a handful of assumptions plus a huge chain of inference. It was just a matter of writing it out precisely. Surely an inevitability. This project was begun by mathematicians and philosophers and it was going pretty well (proving that 1+1=2 for example) up until this chap Gödel comes along and straight up proves it's impossible with his Incompleteness Theorem, if you can do 1+1=2 then Gödel shows how you can write out effectively the equivalent of "This statement is false" and blow up your whole system.

Re: What the CIA WikiLeaks Dump Tells Us: Encryption Works

#232

Post by john61 » Sun, Mar 12, 2017, 11:29 AM UTC

xapata wrote: post #195

john61 wrote: post #187

Earlier quoted context omitted.

Social dependency is not binary. Developers in a company a much more dependent from each other and the boss, than reviewers of free software.

Very true. Maybe I misread your previous comment as being more binary than you intended. Keep in mind that reviewers of free software are also often employees and may have some agenda beyond pure altruism, even if the software isn't copyright of the employer. Open source is big business these days.

Maybe Open Source is big business, but not free software.

Re: What the CIA WikiLeaks Dump Tells Us: Encryption Works

#233

Post by eru » Sun, Mar 12, 2017, 1:06 PM UTC

bdamm wrote: post #223

effie wrote: post #203

Earlier quoted context omitted.

Use of new encryption algorithm on the ciphertext encrypted by the old algorithm.

Sounds good for symmetric crypto, but not for public key exchanges, which is what quantum compute attacks are so far all about. There could be double-tree PKI, where nodes in the tree are represented by two key pairs in different kinds of key spaces, with the different signatures terminating in two ephemeral key pairs, which are then used for key derivation, and the subsequent secret perhaps concatenated and boosted…

Why wouldn't that work? Exchange all n keys with their respective methods in parallel?

Re: What the CIA WikiLeaks Dump Tells Us: Encryption Works

#234

Post by eru » Sun, Mar 12, 2017, 1:08 PM UTC

bad_user wrote: post #93

hendzen wrote: post #79

Earlier quoted context omitted.

Symmetric encryption not being broken doesn't really help you if the encryption key has been exchanged using a (presumably quantum-breakable) form of asymmetric encryption. Most encryption in the wild works this way.

That's understandable, since the point of asymmetric encryption is communication. But people can use symmetric encryption when it's about your own data security (i.e. you encrypt it, you decrypt it). If you're using encryption to keep your data safe (e.g. local files, full disk encryption), then you don't actually need asymmetric encryption.

Even for your own data, asymmetric encryption can be useful.

Eg think you want to encrypt your logs: with asymmetric encryption you can store the public keys on all your servers, encrypt your logs as you generated them and forget the plain text as soon as possible. You keep your private key hidden away on a secure server, and only use it when you actually want to look at your logs (which doesn't happen all that often).

Re: What the CIA WikiLeaks Dump Tells Us: Encryption Works

#235

Post by eru » Sun, Mar 12, 2017, 1:10 PM UTC

doubleunplussed wrote: post #217

Laforet wrote: post #148

Earlier quoted context omitted.

Dropbox is known to have intergration with PhotoDNA, a state program that matches file signature with a database of known illicit images. This would be impossible if the encryption used is irreversible and as far as I know dropbox never claimed otherwise.

Couldn't dropbox hash the images on the client, and upload the encrypted images as well as the hash? No need to upload an unencrypted file to do matching.

Depends on what kind of hashing they do: a scheme like yours using a cryptographic hash would be defeated by just randomly changing a single bit in the image (eg appending some garbage bytes at the end); or re-encoding the jpeg. Of course, it could still catch non-techy people.

Re: What the CIA WikiLeaks Dump Tells Us: Encryption Works

#236

Post by eru » Sun, Mar 12, 2017, 1:12 PM UTC

tialaramex wrote: post #228

acjohnson55 wrote: post #225

Earlier quoted context omitted.

Right. So now you have to figure out how to get a secure RNG into people's hands, so they can create pads. How does that work? Genuinely curious whether there's a reasonable solution.

Devices that produce a trickle of truly random numbers can be produced for a few bucks. They're included in modern CPUs, for example. But that was never the problem. The problem is, now what? To use this OTP you need to securely deliver pads to everybody you'll ever send a message to. So, OTP is practical for a handful of secret agents who'll receive messages of a few dozen words per year from a single controller, an…

Snarkily: a one time pad reduces the problem of exchanging secret messages to exchanging secret keys of the same length..

The only thing that OTP buys you is that you can exchange the pads at your convenience any time before.

Re: What the CIA WikiLeaks Dump Tells Us: Encryption Works

#237

Post by eru » Sun, Mar 12, 2017, 1:14 PM UTC

Retric wrote: post #129

chimeracoder wrote: post #116

Earlier quoted context omitted.

Could you elaborate? I'm not sure I follow. It's been a while since my CS Theory classes.

Basically, you can do 64 bit calculations on a 16 bit traditional computer, it just takes more steps and some RAM. However, to do 64 bit quantum calculations you need a 64 quibit quantum computer. Now, we may be able to build a 64 QC, bout even that is useless for real world encryption. Further, it while it does not take more time to run a 64vs 4096 quibit QC, it does become exponentially harder to build. Sort of lik…

Yes, that's one of the big questions in QC. If people manage to build good error correction for QC some day, scaling will be less of an issue.

Scott Aaronson's blog has some good background information for the layman.

Re: What the CIA WikiLeaks Dump Tells Us: Encryption Works

#238

Post by eru » Sun, Mar 12, 2017, 1:16 PM UTC

tialaramex wrote: post #231

catshirt wrote: post #97

Earlier quoted context omitted.

> the NSA themselves are concerned that quantum computing will be a great threat to encryption in the near future. pardon my ignorance. but, isn't this an inevitability? not just a possibility?

No. For two reasons, a general reason and a specific reason. Firstly, quantum computing at scale _might_ be possible in our universe but it might not. One of the spookiest things that might still be true would be a thing called finite non-local hidden state. In this scenario the whole universe has some sort of hidden state, a bit like the seed value of a Minecraft world. Quantum computing in a universe with finite no…

Our current understanding of Quantum Computing implies Quantum Computing is possible.

So the nice thing about QC research is that we either get shiny new computers to play with, or we learn something new about Quantum Mechanics.

Re: What the CIA WikiLeaks Dump Tells Us: Encryption Works

#239

Post by eru » Sun, Mar 12, 2017, 1:19 PM UTC

MarkMc wrote: post #171

xg15 wrote: post #68

Earlier quoted context omitted.

> WhatsApp say they use end-to-end encryption and they have a strong financial incentive to be telling the truth. I'm not giving much to the various "whatsapp backdoor" allegations but I'm curious to why they'd have financial incentive to provide privacy. Most of their userbase likely still doesn't care about security and they do belong to Facebook - so if anything, they'd have a financial incentive not to use effect…

I guess I would point to the Yahoo security breach as an example of how poor security can have an adverse financial effect on a company valuation and its CEO's remuneration. The Sony hack also comes to mind as something which damaged it's reputation and had an indirect affect on their financial position. If hackers could get access to WhatsApp and dump all messages to Wikileaks it would make the company look very bad…

And even if Facebook / WhatApp's customers don't care about security, their hired geeks do; and being seen as caring about having topnotch security might help with attracting and retaining talent.

Re: What the CIA WikiLeaks Dump Tells Us: Encryption Works

#240

Post by bgrohman » Sun, Mar 12, 2017, 2:17 PM UTC

j-conn wrote: post #213

bgrohman wrote: post #130

Original article on AP News in case your NY Times free article count is up: https://apnews.com/cf84bf54c2954de8baaa5fb6931a84d0/What-the...

Please consider subscribing to high quality newspapers, donating to NPR, or otherwise supporting journalists. IMHO the last few months have driven home the vital public service they provide. I recently read that Tom Hanks sends an espresso machine to the White House press corps every year, while I've been reading their articles in incognito mode.

Thanks, that's a good message. In this case, though, the original article came from AP News, so I don't think there's anything wrong with reading it there.