Astria contributed the following description of Astria Bridge:

The Astria sequencing layer provides a native bridging protocol which allows users bridging assets from the sequencing layer (and thus using IBC) into and out of rollups.

The Astria Rollup Bridge provides functionality for bridging any tokens supported by the Astria sequencing layer into rollups built on top of it.

The design is similar to existing Ethereum L1-to-rollup bridges in that funds are locked on the sequencing layer and a synthetic deposit is derived on the rollup.

Burning the rollup-side funds will then cause the trusted bridge withdrawer service to issue a withdrawal transaction on the sequencing layer—either to a sequencing layer address or to a different chain using ICS20 withdrawals.

Zellic conducted a security assessment for Astria from July 15th to July 31st, 2024. During this engagement, Zellic reviewed Astria Bridge's code for security vulnerabilities, design issues, and general weaknesses in security posture.