Our work
We built a multisig security app and got acquired.
Lucid was a mobile app that showed Gnosis Safe signers what a transaction would do before they approved it. We built it with Nexus Mutual, and OpenCover later acquired it.
- Partner
- Nexus Mutual
- Outcome
- Acquired by OpenCover
- Date
- April 2025
Overview
What was Lucid?
Gnosis Safe is a multisig wallet: a transaction only goes through once enough of its signers approve it. Each signer is a security check, and Lucid was the app we made for them.
We built it in partnership with Nexus Mutual, a DeFi insurance protocol that offers cover against risks such as smart contract hacks.
The problem
The problem it solved
The Bybit exploit showed how badly this can go. Attackers spoofed the interface, signers approved a malicious contract upgrade without seeing what it really did, and about $1.5 billion was lost.
A signature only protects a multisig if the signer knows what the transaction will do and signs from a device they can trust. We proposed Lucid to give signers both.
Before a signer approved anything, the app simulated the Safe transaction and showed exactly what it would do. The signer could then approve it from their phone, which acted as the secure device for signing.
Outcome
What happened
OpenCover acquired Lucid. OpenCover helps individuals and institutions buy cover against onchain risks, and Nexus Mutual is one of the cover providers it works with.
Contact our team
We take 4 protocols per quarter. Formal verification demands deep focus. We'd rather verify fewer contracts well than many poorly.
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Learn more
The original Lucid proposal on the Safe forum.
OpenCover and Nexus Mutual.
What is a formal proof? How we check what code does today.