3 ms·

Show HN: Beamsplitter – Hash function that uses only S-boxes

18 points by archivist1 7y ago

cmpakawangi 7y ago
Supergirl 510 1080p.Megashare Watch this link! : https://bit.ly/3789vEF https://bit.ly/3789vEF http://en.ntclbd.com/2020/01/top-10-supergirl-s5-episode-10.html http://en.ntclbd.com/2020/01/top-10-supergirl-s5-episode-10.... http://www1.tapashpaul.com/2020/01/megashare-supergirl-s5-episode-10.html http://www1.tapashpaul.com/2020/01/megashare-supergirl-s5-ep... https://new.rsl.org.bd/2020/01/series-supergirl-s5-episode-10.html https://new.rsl.org.bd/2020/01/series-supergirl-s5-episode-1... https://taskins.blogspot.com/2020/01/season-5-supergirl-episode-10.html https://taskins.blogspot.com/2020/01/season-5-supergirl-epis... http://www2.zenskin.com.bd/2020/01/supergirl-s5-episode-10.html http://www2.zenskin.com.bd/2020/01/supergirl-s5-episode-10.h... http://en-us.accessit-server.com/2020/01/supergirl-s5-episode-10.html http://en-us.accessit-server.com/2020/01/supergirl-s5-episod... http://vip.fashion-imperial.com/2020/01/supergirl-s5-episode-10.html http://vip.fashion-imperial.com/2020/01/supergirl-s5-episode... http://www.tvpromosdb.ga/2020/01/123mov-supergirl-bottle-episode-10.html http://www.tvpromosdb.ga/2020/01/123mov-supergirl-bottle-epi... http://en.ntclbd.com/2020/01/top-10-bottle-episode-10-supergirl.html http://en.ntclbd.com/2020/01/top-10-bottle-episode-10-superg... http://www1.tapashpaul.com/2020/01/megashare-bottle-episode-10-supergirl.html http://www1.tapashpaul.com/2020/01/megashare-bottle-episode-... https://new.rsl.org.bd/2020/01/series-bottle-episode-10-supergirl.html https://new.rsl.org.bd/2020/01/series-bottle-episode-10-supe... https://taskins.blogspot.com/2020/01/links-bottle-episode-10-supergirl.html https://taskins.blogspot.com/2020/01/links-bottle-episode-10... http://www2.zenskin.com.bd/2020/01/the-bottle-episode-10-supergirl.html http://www2.zenskin.com.bd/2020/01/the-bottle-episode-10-sup... http://en-us.accessit-server.com/2020/01/the-bottle-episode-10-supergirl.html http://en-us.accessit-server.com/2020/01/the-bottle-episode-... http://vip.fashion-imperial.com/2020/01/the-bottle-episode-10-supergirl.html http://vip.fashion-imperial.com/2020/01/the-bottle-episode-1...
arkadiyt 7y ago
Let's ignore for a second the question of security (is it collision/pre-image resistant? Dieharder says nothing about this). As a developer, is the fact that it only uses S-boxes supposed to be beneficial to me somehow? Does this mean it runs faster? Uses less memory? Is it an academic exercise? Why would I use this over a different hash function?
- rurban 7y ago
  It's not even resistant to added \0, so you can trivially create an arbitrary number of collisions. It fails all smhasher tests and is pretty slow. There's a reason other hashes do more than just sbox mixing. It's a proof of concept of a bad hash function. But it works fine on javascript, I guess.
- maxfan8 7y ago
  It's probably an academic exercise (perhaps to demonstrate how not to make a secure hash function). It's is pretty poorly designed.
  - sneak 7y ago
    As someone who knows a bit about how hash functions work and what properties they are supposed to have when well-designed, but has no knowledge of how to invent them: would you elaborate either directly or with links? What about it is poorly designed? Why? What would make it better?
    - maxfan8 7y ago
      Sorry - just saw this! So think of the sbox as a function. What happens if you apply the function over and over again? The order of a group like that would be small (particularly since the sboxes are random). Also, the output space of the hash function would be quite restricted as a result of the group order being low.
- SCHiM 7y ago
  I'm reasonably sure it's in jest: """ I went to random.org and generated 32 sets of 256 no-repeat numbers between 0 and 255 inclusive. """ We have someone with the practical cryptographic knowledge to design their own cryptographic code, but they grab their random numbers from a website... ;)
  - clarry 7y ago
    Also posting dieharder results as validation (and the only kind of validation!) smells like a joke.
xscott 7y ago
Saving a Google search for those (like me) who don't know what S-boxes are: https://en.wikipedia.org/wiki/S-box https://en.wikipedia.org/wiki/S-box
mmastrac 7y ago
> I went to random.org and generated 32 sets of 256 no-repeat numbers between 0 and 255 inclusive. One suggestion I'd have here would be using "nothing-up-my-sleeve" numbers like pi/e/log2 in hex. [1] [1] https://en.wikipedia.org/wiki/Nothing-up-my-sleeve_number https://en.wikipedia.org/wiki/Nothing-up-my-sleeve_number
cafxx 7y ago
I sincerely hope the author will urgently and clearly mark the repo as a toy/demo/do not use for anything important in the readme.

18 points by archivist1 7y ago

Supergirl 510 1080p.Megashare Watch this link! : https://bit.ly/3789vEF https://bit.ly/3789vEF http://en.ntclbd.com/2020/01/top-10-supergirl-s5-episode-10.html http://en.ntclbd.com/2020/01/top-10-supergirl-s5-episode-10.... http://www1.tapashpaul.com/2020/01/megashare-supergirl-s5-episode-10.html http://www1.tapashpaul.com/2020/01/megashare-supergirl-s5-ep... https://new.rsl.org.bd/2020/01/series-supergirl-s5-episode-10.html https://new.rsl.org.bd/2020/01/series-supergirl-s5-episode-1... https://taskins.blogspot.com/2020/01/season-5-supergirl-episode-10.html https://taskins.blogspot.com/2020/01/season-5-supergirl-epis... http://www2.zenskin.com.bd/2020/01/supergirl-s5-episode-10.html http://www2.zenskin.com.bd/2020/01/supergirl-s5-episode-10.h... http://en-us.accessit-server.com/2020/01/supergirl-s5-episode-10.html http://en-us.accessit-server.com/2020/01/supergirl-s5-episod... http://vip.fashion-imperial.com/2020/01/supergirl-s5-episode-10.html http://vip.fashion-imperial.com/2020/01/supergirl-s5-episode... http://www.tvpromosdb.ga/2020/01/123mov-supergirl-bottle-episode-10.html http://www.tvpromosdb.ga/2020/01/123mov-supergirl-bottle-epi... http://en.ntclbd.com/2020/01/top-10-bottle-episode-10-supergirl.html http://en.ntclbd.com/2020/01/top-10-bottle-episode-10-superg... http://www1.tapashpaul.com/2020/01/megashare-bottle-episode-10-supergirl.html http://www1.tapashpaul.com/2020/01/megashare-bottle-episode-... https://new.rsl.org.bd/2020/01/series-bottle-episode-10-supergirl.html https://new.rsl.org.bd/2020/01/series-bottle-episode-10-supe... https://taskins.blogspot.com/2020/01/links-bottle-episode-10-supergirl.html https://taskins.blogspot.com/2020/01/links-bottle-episode-10... http://www2.zenskin.com.bd/2020/01/the-bottle-episode-10-supergirl.html http://www2.zenskin.com.bd/2020/01/the-bottle-episode-10-sup... http://en-us.accessit-server.com/2020/01/the-bottle-episode-10-supergirl.html http://en-us.accessit-server.com/2020/01/the-bottle-episode-... http://vip.fashion-imperial.com/2020/01/the-bottle-episode-10-supergirl.html http://vip.fashion-imperial.com/2020/01/the-bottle-episode-1...

arkadiyt 7y ago

Let's ignore for a second the question of security (is it collision/pre-image resistant? Dieharder says nothing about this). As a developer, is the fact that it only uses S-boxes supposed to be beneficial to me somehow? Does this mean it runs faster? Uses less memory? Is it an academic exercise? Why would I use this over a different hash function?

rurban 7y ago
It's not even resistant to added \0, so you can trivially create an arbitrary number of collisions. It fails all smhasher tests and is pretty slow. There's a reason other hashes do more than just sbox mixing. It's a proof of concept of a bad hash function. But it works fine on javascript, I guess.
maxfan8 7y ago
It's probably an academic exercise (perhaps to demonstrate how not to make a secure hash function). It's is pretty poorly designed.
- sneak 7y ago
  As someone who knows a bit about how hash functions work and what properties they are supposed to have when well-designed, but has no knowledge of how to invent them: would you elaborate either directly or with links? What about it is poorly designed? Why? What would make it better?
  - maxfan8 7y ago
    Sorry - just saw this! So think of the sbox as a function. What happens if you apply the function over and over again? The order of a group like that would be small (particularly since the sboxes are random). Also, the output space of the hash function would be quite restricted as a result of the group order being low.
SCHiM 7y ago
I'm reasonably sure it's in jest: """ I went to random.org and generated 32 sets of 256 no-repeat numbers between 0 and 255 inclusive. """ We have someone with the practical cryptographic knowledge to design their own cryptographic code, but they grab their random numbers from a website... ;)
- clarry 7y ago
  Also posting dieharder results as validation (and the only kind of validation!) smells like a joke.

xscott 7y ago

Saving a Google search for those (like me) who don't know what S-boxes are: https://en.wikipedia.org/wiki/S-box https://en.wikipedia.org/wiki/S-box

mmastrac 7y ago

> I went to random.org and generated 32 sets of 256 no-repeat numbers between 0 and 255 inclusive. One suggestion I'd have here would be using "nothing-up-my-sleeve" numbers like pi/e/log2 in hex. [1] [1] https://en.wikipedia.org/wiki/Nothing-up-my-sleeve_number https://en.wikipedia.org/wiki/Nothing-up-my-sleeve_number

cafxx 7y ago

I sincerely hope the author will urgently and clearly mark the repo as a toy/demo/do not use for anything important in the readme.