Official MASTR logo MASTR Support the work
Contents
← Wiki home

DeFi & governance

Lock-and-mint bridges: the token depends on both sides

A destination-chain asset can represent a claim on funds controlled elsewhere.

Technical reference · cross-chain assets · 1 min read

Research articles and reference entries are published in English. Navigation is available in seven languages.

In this article
  1. The representation
  2. Where a failure becomes an unbacked balance
  3. Sources and originals

The representation

In a lock-and-mint design, an asset is deposited into a source-chain custody mechanism and a corresponding representation is issued on a destination chain. Returning normally requires destroying or surrendering the representation and releasing the original asset through the bridge's rules.

The destination token therefore depends on more than its own transfer contract. It depends on the source custody, message validation, operator or validator permissions, pause functions and the route back to the underlying asset. A familiar ticker cannot identify all of those dependencies.

In a lock-and-mint design, a destination token depends on the source lock and message-verification rules. Accepting a false message can create claims without the corresponding locked assets. Native cross-chain transfers can use different designs.
In a lock-and-mint design, a destination token depends on the source lock and message-verification rules. Accepting a false message can create claims without the corresponding locked assets. Native cross-chain transfers can use different designs.
Open full-size diagram

Where a failure becomes an unbacked balance

If a bridge accepts a false deposit message, it may issue a representation without matching collateral. If the locked assets are stolen, correctly issued destination tokens can lose their backing. In either case, the destination blockchain can continue processing valid token transfers while the economic claim is impaired.

Bridge asset identity explains how to identify the specific representation. Ronin provides a historical bridge incident, and data availability addresses a separate dependency that is often incorrectly treated as equivalent to proof of backing.

Sources and originals

Related reading

MASTR

Support independent research

The investigations, original evidence and guides here are free to read. Voluntary donations help fund the research and keep MASTR’s tools available.

Open wallet