Large crypto holders face well-resourced adversaries using attack vectors that multisig alone cannot address. This talk walks through six categories of threat: simulation spoofing, address poisoning, frontend compromises, supply chain attacks, insider threats, and kidnapping or duress scenarios.

Each attack exploits a common weakness: the finality of signed transactions and the opacity of what's actually being approved. We'll examine real incidents, break down why existing solutions fail, and introduce a defense framework centered on post-signature review windows and cancellation authority.

The session concludes with a demonstration of Kleidi, a wallet implementation that operationalizes this framework through timelocks, policy engines, and guardian services. Attendees will leave with a threat model they can apply to custody architecture reviews and a concrete reference for how reversibility changes the security calculus.