News for hackers. Stuff that matters.

A comment on Milk Sad: Weak Entropy in libbitcoin (bc) seed generation.

Re:Milk Sad: Weak Entropy in libbitcoin (bc) seed generation by mkj on Wednesday August 09, 2023 @12:17AM (#37058627)
Was the code seeding by seconds since epoch, or nanoseconds since epoch truncated to 32 bits? Broken either way.

https://github.com/libbitcoin/libbitcoin-system/blob/a1b777f...

        const auto now = high_resolution_clock::now();
        return static_cast<uint32_t>(now.time_since_epoch().count());
[ Parent | on HN ]
Re:Milk Sad: Weak Entropy in libbitcoin (bc) seed generation by ryanatdistrust on Wednesday August 09, 2023 @08:25AM (#37061595)
Nanoseconds since epoch, which means eventually it does loop around, so at the very least it's not possible to generate a specific wallet by knowing when it was first used.
[ Parent | on HN ]
Re:Milk Sad: Weak Entropy in libbitcoin (bc) seed generation by infofarmer on Wednesday August 09, 2023 @08:42AM (#37061783)
A quick search says it's actually ticks, which is OS and machine dependent (kernel tunable). Nanosecond resolution is not enough for a seed if it's a real datetime, so the 32-bit truncation is a separate problem.
[ Parent | on HN ]