From 4e1f16e4001722603c231dddebc631988fdb8d34 Mon Sep 17 00:00:00 2001 From: Joey Hess Date: Thu, 6 Oct 2016 17:28:53 -0400 Subject: thought --- TODO | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/TODO b/TODO index 3d4ff54..17f7cb9 100644 --- a/TODO +++ b/TODO @@ -32,11 +32,20 @@ Wishlist: are passphrase protected anyway.. * Don't require --totalshares and --neededshares on restore when unusual values were used for backup. + The difficulty is that the number of needed shares cannot be determined by looking at shares, and guessing it wrong will result in combining too few shares yielding garbage, which it will take up to an hour to try to decrypt, before it can tell that more shares are needed. + This could be dealt with by including the number of needed shares in the serialization of Share, but then an attacker could use it to partition shares from servers. If only one person uses --neededshares=5, the attacker can guess that all their shares go together. + + What about including the number of needed shares in the name? Since that's + hashed, it's not visible to an attacker. Keysafe would need to try names + with 2 shares, then 3, etc, and once it found shares, it would know the + number needed. It should also be possible to avoid breaking backwards + compatability, by only including the number of shares in the name when + it's not the standard number. -- cgit v1.2.3