I thought Civic (https://www.civic.com) was one of the most interesting projects to come out of the blockchain space for secure identity, but haven’t really seen it adopted anywhere. Facebook sign in is everywhere, but Facebook is also completely untrustworthy when it comes to personal data and so I tend to avoid it whenever possible. This idea of sharing attributes seems interesting but does it go any further than “This app wants access to your email address, contacts, and photos” that already exists?
Blockchains have very little to do with "secure identity", and in fact more frequently serve to damage the security of the individual. If everything is recorded in a central ledger, how long do you think it takes for oppression to emerge?
As opposed to being stored in Google/Facebook's databases? I don't know if blockchain is the answer, but I would prefer not to trust any of these large corporations and use a decentralized identity system where no third-party has control of my identity information.
In self sovereign identity systems based on verifiable claims, attributes are attested through signed claims on digital identifiers that the user control (e.g. a public key). Blockchains here are the most effective mean to implement claim revocation: if someone who produced a claim wants to revoke it, he writes that on a blockchain.
Disclaimer: I work for Hyperledger. One of our projects, Hyperledger Indy, is used in particular in Zug as the basis for an eVoting program. Searching for "Hyperledger Indy Zug" turned up some press releases and discussions about it
