Secret Key — timing lesson
Study the timing transcript and identify why character-by-character comparisons can disclose secret prefixes.
TIMING TRANSCRIPT
prefix length 0: 101 cycles
prefix length 1: 108 cycles
prefix length 2: 117 cycles
lesson: comparison time changes with the matching secret prefix
Attribution: Adapted from Crate-CTF, 2025 challenge “Secret Key” by Erik. Used under the MIT License; flags and secrets were replaced for GisVuln. See source and license details.
This GisVuln adaptation is self-contained and does not contact the original challenge infrastructure.