In some implementations, a data unit may be hashed to generate a hash. A cryptographic structure, such as a Merkle tree or other cryptographic structure, maybe generated based on the hash and published on a block chain or distributed ledger. A proof associated with the data unit may be provided. The proof may allow for independent verification that the data unit is certified. Responsive to obtaining the data unit as at least one data unit to be verified, the data unit may be hashed. The associated proof may be obtained, where the obtained proof includes an index describing a position of the hash among one or more other hashes in the published cryptographic structure. The cryptographic structure may be reconstructed based on the index of the proof. Certification of the data unit may be verified by proving that the hash belongs to a root of the published cryptographic structure.