Cryptography OpenSSH adds post-quantum key exchange

OpenSSH adds post-quantum key exchange
Expressing a computation as an NP statement
Determine the encoding matrix M
If the NSA keeps encrypted data for as long as it takes to decrypt it, then does that mean they are storing 50% of the worlds traffic per day, every day?
Is it safe to update Veracrypt to latest version?
[Question] - Yet Another Post Trying to Get Help With SSL on Python

Posted: 19 Apr 2019 12:15 PM PDT

from https://www.openssh.com/txt/release-8.0

ssh(1), sshd(8): Add experimental quantum-computing resistant key exchange method, based on a combination of Streamlined NTRU Prime 4591⁷⁶¹ and X25519.

Protocol seems to be lifted from tinyssh. I think the most important thing is that there is now support for a KEM that can be extended to any KEM that gets standardized instead of relying on a DH type key exchange.

submitted by /u/eeget9Eo
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Expressing a computation as an NP statement

Posted: 20 Apr 2019 12:32 AM PDT

Good Morning

I am currently studying zero knowledge proofs. In 1991 Goldreich, Micali and Wigderson have shown, that for every language in NP we can construct a ZKP. Matthew Green decribes in his blogpost (https://blog.cryptographyengineering.com/2017/01/21/zero-knowledge-proofs-an-illustrated-primer-part-2/), that we can "just" translate our problem into a boolean circuit, translate it into a graph and run the GMW protocol (even tho this is very inefficient, I would like to understand how this would be approached).

Now I would like to know, how this relates into practice. Looking at the libsnark library (https://github.com/scipr-lab/libsnark) they give an example of the representation of a computation as a NP statement: "The C program foo, when executed, returns exit code 0 if given the input bar and some additional input qux."

This is how I understand this: "I have some secret inputs. To construct a ZKP, I would have to write a C program that only returns with exit code 0 on this input and then follow the steps from above." Do I get this somewhat correct?

Or would it be easier to understand which problems can be represented as a boolean circuit and which not (is there any easy to understand work on this?)

Is there any work (books/papers) on the encoding of a computation as a NP statement?

submitted by /u/AlreadyAdmin
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Determine the encoding matrix M

Posted: 19 Apr 2019 11:30 PM PDT

Just a little question I have floating around that I don't know how to tackle. This is not a homework problem.

Suppose there is an (mxn) matrix M that acts on bitstrings b of {0,1}^(m) mapping them into bitstrings B of {0,1}^(n). How many bistrings B must you know to determine M (if it is even possible?). If not, can you do it by knowing some of the b's alone? If not , how many maps Mb -> B do you need to know?

Relation to crypto: I was thinking about whether or not I could create a secure password with a similar mapping on keyboard inputs. Something like "I type in an English word password of some length, and under some mapping that only I know it is changed to some complicated, longer thing. How many passwords can be stolen before my "map" is figured out?

-I don't know if this is close enough to crypto, I just don't have people to ask that are interested in this. I suppose there's probably a simple solution that I can't figure the linear algebra to.

submitted by /u/JShrub
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If the NSA keeps encrypted data for as long as it takes to decrypt it, then does that mean they are storing 50% of the worlds traffic per day, every day?

Posted: 19 Apr 2019 09:27 PM PDT

I read an estimate that around 50% of all internet traffic is encrypted these days, and the article from the Snowden leaks that talked about the NSA keeping all encrypted data was from 2013, when there probably wasn't as much encryption going on.

So... how the hell do you store so much data? Do you really believe that the NSA is keeping half of the internets data (per day) stored until they can crack it with quantum computers?

https://www.forbes.com/sites/andygreenberg/2013/06/20/leaked-nsa-doc-says-it-can-collect-and-keep-your-encrypted-data-as-long-as-it-takes-to-crack-it/

https://www.google.com/amp/s/www.cbronline.com/news/internet-encryption-sandvine/amp/

submitted by /u/ZeldaPrince
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Is it safe to update Veracrypt to latest version?

Posted: 19 Apr 2019 12:14 PM PDT

I have a FDE with Veracrypt 1.22, i saw there's new version out but I saw some dudes complaining that when he updated he was able to decrypt... so my question is: is it safe to update to the latest version, and if so, what is the correct way to do it? I have never updated Veracrypt, since I encrypted with FDE I've stick to 1.22 but I saw they fixed some stuff since then. I think this is the latest version (1.24-Beta5):

https://www.veracrypt.fr/en/Release%20Notes.html

But it's beta version, so im not sure... 1.23 I guess its not beta anymore. But for instance, this guys is complaining he can't decrypt:

https://sourceforge.net/p/veracrypt/discussion/general/thread/24402bfdf1/

So I don't know what to do. I want to upgrade since there were some interesting fixes, for instance 1.23 hotfix 2 includes:

Fix low severity vulnerability inherited from TrueCrypt that allowed reading 3 bytes of kernel stack memory (with a rare possibility of 25 additional bytes).

But how do I know it will work and im not left with a drive that cannot be decrypted?

submitted by /u/cryptoman_007
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[Question] - Yet Another Post Trying to Get Help With SSL on Python

Posted: 19 Apr 2019 09:27 AM PDT

submitted by /u/GettingKittyWithIt
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