A storage address that is a hash of the file.

Your encrypted wallet backup is larger than the XRP Ledger will hold, where fields cap at 256 bytes. So we store it on public storage and keep a small pointer on-chain, a content ID, or CID, computed by hashing the file's own bytes.

A normal web link names a server and path, then trusts it to return the right file. A CID instead names the content. Change one byte and the CID changes, so it resolves only to the exact bytes behind it.

That is what lets the backup sit in the open. Any gateway can serve it, and your device re-hashes what it gets and checks that against the CID. A swapped file fails to match its address.

The ledger records which CID is yours, so your device can confirm the file before any restore. A gateway can hold the bytes and still cannot change which bytes your address accepts.