Summary
Ketju does not approve B² Buzz: B² discloses no custody, and holders cannot withdraw. In July 2026, an attacker with privileged access drained a B² Network contract. These are the clearest grounds of any Bitcoin bridge Ketju has reviewed. B² Buzz is a staking and points event on B² Network (BSquared), the Bitcoin Layer 2 beneath UniRouter, which Ketju also does not approve. B²’s own bridge documentation names no custody setup and says "the withdraw function is not yet available." The bridge takes deposits only and offers no route back to native BTC. The July 2026 exploit took about $3.86M through upgrade authority over a token staking contract. The draining wallet had held that authority since 2025 and lost it only after the theft. Independent analysts read that as a credible sign of insider access, and the team has not refuted it.
Review triggers
- A withdrawal or redemption function is built, documented, and shown to work at proposed size
- Custody architecture and named signing parties are publicly disclosed
- An independent post-mortem of the July 2026 exploit is published, confirming whether the privileged access came from an insider, with the fix verified
- Twelve consecutive months with no further privileged-access incident on a token or bridge contract, counted from the July 2026 exploit
Facts
- Verdict
- Not approved
- Type
- Other
- Chains examined
- Ethereum
- Reviewed
- Last confirmed