After exploring and trying out blockcerts for a month, I still fail to understand this. I know that, to verify a blockcerts credential, the issuer must host an issuer profile with its public keys. Verifier checks the hash against blockchain to guarantee immutability, and checks the signature against the issuer’s listed public keys to guarantee authenticity.
From my understanding, simply hashing and signing the hash is enough to guarantee both immutability and authenticity (what OpenBadges do), then blockchain is just extra and not needed? In blockcerts, if the hosted issuer is down, authenticity can’t be verified. That’s the same as just using hash and signature. It’s still reliant on the issuer. What’s the advantage of blockcerts then?