[OneDeuxTriSeiGo]

There's certainly application outside of currencies. Bluesky/atproto for example is built on DIDs (decentralised IDs) and IPLD (the data format/standard of IPFS). Both are very heavily rooted in cryptocurrency tech.

There's a joke in the atproto community that it's a blockchain but without the currency because of this.

[dboreham]

Neither DID nor IPLD have anything to do with cryptocurrency from a technical perspective. At least no more than do X.509 and ssh.

[OneDeuxTriSeiGo]

IPLD is literally a merkle tree data structure format standardised by IPFS which is heavily rooted in cryptocurrency and in fact has its own cryptocurrency created by the IPFS devs: Filecoin.

DIDs were created by cryptocurrency orgs. The standard was created by a bunch of cryptocurrency groups working with the W3C and the entire time it was being developed, it was derided by non-cryptocurrency people as just another way for cryptocurrency to scam people. It doesn't stop being related to cryptocurrency once you realise it's useful.