Think of the blockchain as an “append-only” ledger with a transaction order that is distributed across many entities, with each entity keeping an identical copy of the ledger. Every record in the ledger is time-stamped, immutable, and independently verifiable.
A hash of the whole structure containing the files’ fingerprints is recorded into the blockchain. The authenticity of those files can be independently confirmed by any party (even one not doing business with Acronis) that has access to the blockchain.