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On 2026-07-09 @octralex restarted the HFHE challenge (v2), stating the original…

2026-07-09 · 21:57 UTC ·@octralex ·0 min read

Brief

Octra (@octralex) relaunched the HFHE challenge as v2 on 2026-07-09, claiming v1 exposed a public artifact that enabled brute-force attacks and has been fixed. The challenge posts 500,000 OCT at octC5eR9pLGKbpzTbDgHowkFt8HW7LZYb2gzehzxHamxuAZ and offers another 500,000 OCT for a verified recovery plus explanation; generic reports and GitHub issues will be removed or ignored until funds move.

Why it matters

On 2026-07-09 @octralex restarted the HFHE challenge (v2), stating the original challenge contained an unnecessary public artifact that made it brute-forceable and that v2 removes that attack path.

Key details

  • The challenge funds 500,000 OCT in wallet octC5eR9pLGKbpzTbDgHowkFt8HW7LZYb2gzehzxHamxuAZ and promises an additional 500,000 OCT (total 1,000,000 OCT) to anyone who recovers the private key and explains the method; generic "breaks" will be ignored until funds are moved and GitHub issues will be removed.
Source evidence

Restarted the challenge: the first one included an unnecessary public artifact that made it bruteforceable. It was not a clean HFHE challenge and v2 removes that path. Unfortunetely, previous point still stands and unless funds are moved, every generic "break" will be ignored.

octra (@octra)

open HFHE challenge v2

this wallet holds 500,000 OCT:
octC5eR9pLGKbpzTbDgHowkFt8HW7LZYb2gzehzxHamxuAZ

recover its private key, tell us how you did it and receive another 500,000 OCT, for a total of 1 million. do not submit issues, they will be removed! github.com/octra-labs/hfhe-c…

Link

GitHub - octra-labs/hfhe-challenge

Contribute to octra-labs/hfhe-challenge development by creating an account on GitHub.
github.com

— https://nitter.net/octra/status/2075336875322032268#m