Verifiable Storage

Verifiable storage allows a cloud customer to check whether her (Big) data is stored correctly at the cloud server provider. As previously mentioned, classical data integrity techniques are not suitable anymore since they require the customer to download the entire data together with the integrity proof computed by the cloud. TREDISEC tackles this specific problem and currently investigates existing solutions that can be classified into two categories: Proof of Data Possession (PDP) and Proof of Retrievability (PoR).


Proofs of retrievability for data replications. It allows the data replication be handled by the cloud provider, who will then generate proofs of retrievability of these replicas upon user attestation.


De-duplication on the authenticators used for Proofs of Retrievability across multiple users. Relying on key-message homomorphic encryption, the cloud providers are able to merge the PoR authenticators generated by different users using different credentials and the merged authenticators is verifiable by all users.

ML-POR with MLKeygen

Message Locked PoR and Message locked key generation. This primitive enables clients to verify the retrievability of their files while also allowing file-based deduplication based on a dedicated message-locked key generation. Since all keying material are depending on the file itself the encryption and encoding of the files remain the same if the file is the same.


Proofs of Retrievability (PoR) are cryptographic proofs that enable a cloud provider to prove that the tenant can retrieve his file in its entirety. A tenant can ask the cloud provider to provide such proofs of a requested file without the need to download the file The aim of providing the PoR primitive is to provide strong assurance of storage integrity to the tenants.