Green-Sky/p2prng
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

update readme

Browse Source
This commit is contained in:
Green Sky 2024-08-02 12:17:09 +02:00
parent dd47e44254
commit e7a77ef502
No known key found for this signature in database
1 changed files with 18 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

29
README.md
View File

@ -3,7 +3,7 @@
As long as you can contribute an unpredictable (random) number of your choosing, the algorithm will make sure the outcome is unpredictable. As long as you can contribute an unpredictable (random) number of your choosing, the algorithm will make sure the outcome is unpredictable.
First a public "vote" is held, where everyone secretly generates an unpredictable number and shares a digest to later verify it (HMAC in this proposal). First a public "vote" is held, where everyone secretly generates an unpredictable number and shares a digest to later verify it (HMAC in this lib).
After receiving all HMACS, one sends out the number and starts receiving all the others and verifies them. After receiving all HMACS, one sends out the number and starts receiving all the others and verifies them.
Now we have random numbers that need to be combined in a predetermined way that mangles them seemingly randomly and temper proof (very expensive). Now we have random numbers that need to be combined in a predetermined way that mangles them seemingly randomly and temper proof (very expensive).
For this a hashing chain is chosen. For this a hashing chain is chosen.
@ -11,36 +11,43 @@ For this a hashing chain is chosen.
# Algo # Algo
## init ## init
InitialState (IS) contains a unique(-ish) id, to uniquly identify this random number InitialState (IS) contains a unique(-ish) id, to uniquly identify this random number generation
+ any extra data thats usecase dependent. (like the set of cards we are choosing from) + a list of all peers participating, ideally with a unique id
+ any extra data, usecase dependent. (like a set of cards we are choosing from)
-> hashed to get a fixed sized SI ## rng
SI = H(id + user data) Use an unpredictable rng. Simple prng dont cut it, since their state can be reconstructed form very few numbers.
## rng?
use an unpredictable rng. Simple prng dont cut it, since their state can be reconstructed form very few numbers.
(use system crng or seed own chacha crng with system crng ...) (use system crng or seed own chacha crng with system crng ...)
This library provides `p2prng_gen_and_auth()`, that provides you with a random number and also directly computes mac and key.
IS is mixed into the random number.
## hmac ## hmac
message is the rng (while possibly variable in size, should be same as output of H() ) message is the rng (while possibly variable in size, should be same as output of H() )
key is random key is random
send HMAC to everyone send HMAC to everyone
`p2prng_auth_create()` can be used here, if you dont already use `p2prng_gen_and_auth()`.
## collection ## collection
wait for everyone elses HMAC wait for everyone elses HMAC
send out secret message (rng) and key send out secret message (rng) and key
verify everyone elses message verify everyone elses message using `p2prng_auth_verify()`
do not proceed until everything is verified. do not proceed until everything is verified.
either hardblock if someone is not responding (to prevent a retry-attack) or exclude unresponsive/lying peer in next (retry) generation. either hardblock if someone is not responding (to prevent a retry-attack) or exclude unresponsive/lying peer in next (retry) generation.
## post processing ## post processing (combining)
Combine IS with all the numbers
combine IS with all the numbers Using `p2prng_combine_init()` and `p2prng_combine_update()`.
effectively doing:
```
for each M do for each M do
H(M + prevH) H(M + prevH)
result = H(IS + prevH) result = H(IS + prevH)
```