192 reputation
6
bio website xavierm02.net
location France
age 21
visits member for 1 year, 11 months
seen Nov 8 at 1:55

French. Loves JavaScript.


Aug
12
comment Is there an encryption that is only reversible with a key?
There is the one time pad.
Aug
10
comment $(k, n)$ threshold secret sharing to $(k+k', n + n')$ without reissuing all shares
You second point about $x$ having to be private is really interesting (and really tricky). I never would've though about it (O_O) but I think the trustworthy group fixes that too. I'm not sure though. Anyway, I'm not going to make the $x$s public. But since I was thinking of only updating $y$ if a share was compromised, I'll probably have to rework my recovery protocol. I'll think about it and ask another question if I'm not sure :)
Aug
10
comment $(k, n)$ threshold secret sharing to $(k+k', n + n')$ without reissuing all shares
I edited and added a lot of detail. I think that the trustworthy group of shareholders that accept to delete their shares makes it possible.
Aug
10
comment $(k, n)$ threshold secret sharing to $(k+k', n + n')$ without reissuing all shares
The parties that I see often can be trusted to delete their own shares (and not compromising them). We can also, if necessary, assume that whenever a share is compromised, I know it.
Aug
10
comment $(k, n)$ threshold secret sharing to $(k+k', n + n')$ without reissuing all shares
Not really. But the adversary can only figure out who the people are and then try to find where they hid the key. Why?
Aug
9
comment Recover from compromised shares with Shamir Secret Sharing
Since I use secret sharing to back up a key that I use daily, I totally missed the fact that you need the secret to issue new shares. Thanks for pointing that out :-)
May
10
comment Encrypt HDD with keyfile and password and allow backing up the keyfile with secret sharing
@e-sushi : The compiled default in Debian: aes-xts-plain64.
May
10
comment Encrypt HDD with keyfile and password and allow backing up the keyfile with secret sharing
@RickyDemer : No idea. That's what the tutorials I read did.
May
2
comment Back up an information as $n$ pieces and require exactly $n-1$ to recover it
Thank you. The Shamir Secret Sharing is exactly what I wanted :)