HTB - Crypto: Shamir’s Secret

Challenge Summary

  • Name: Shamir’s Secret
  • Category: Crypto
  • Difficulty: Medium
  • Goal: Recover the hidden flag from a custom share-encryption service.
 

Zero

CTF notes by Zero

Breaking mixed real/fake polynomial shares over modulo 2^1024 using 2-adic filtering and Smith Normal Form.

2026-02-27

Tags

#ctf #htb #cry