Too Secure (Cyber, Medium, 237 pts)

Author: Vadim Davydov (@vadimdavydov)

Find a vulnerability in our novel message commitment system. Read the paper here: too_secure.pdf

Enter decimal r2 value as the flag. Flag format here is NOT cybrics{...}

13:43 — to clarify, x in the scheme is the message we're committing to

18:50 — there was a discrepancy between the checker and specification, please resubmit your number if you think you've been affected. Though that shouldn't be the case, according to the logs

Artem Vasilyev, [25.07.20 19:58]
@mrvos @vadimdavydov "Too Secure", section "Commitment", is c = G * h^r calculated modulo P?

Vadim Davydov, [25.07.20 20:24]
Yes