ltox: Cross-chain DIDs

[jasny]

By default, an LTO identity node will only resolve DIDs based on LTO network addresses. It's possible to configure the service to index DIDs based on addresses of other blockchains, like Ethereum or Bitcoin.

DIDs with the method "ltox" can be resolved by LTO Network identity nodes that support cross-chain identifiers.

The method-specific string is comprised of a CAIP-2 blockchain ID and an address on that specific chain.

did:ltox:eip155:1:0xab16a96d359ec26a11e2c2b3d8f8b8942d5bfcdb

ltox-did = "did:ltox:" chain-id ":" address
chain-id = chain-namespace + ":" + chain-reference
chain-namespace = {3,16}\*( ALPHA / DIGIT )
chain-reference = {1,47}\*( ALPHA / DIGIT )
address = {1,63}\*( ALPHA / DIGIT )

The method-specific string is case-sensitive.

Supported chains

Currently, only eip155 is supported. This address scheme is used by Ethereum and other EVM-based blockchains like Binance Smart Chain.

See documentation

Also see https://github.com/ChainAgnostic/CAIPs

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You should be able to configure which chains to index. Initially, you can only configure eip155.

The following config will index DIDs for Ethereum and Binance chain.

{
    "cross_chain": ["eip155:1", "eip155:56"]
}

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When indexing, check the key type. For instance for eip155, only index sep256k1 keys.