HyQloud is a software solution that runs over Quantum Key Distribution network. The full-stack implementation of HyQloud over a QKD network results in a hybrid classical-quantum infrastructure that provides long-term security for data storage.

At the heart of HyQloud is the LINCOS protocol. This protocol combines a Proactive Secret Sharing scheme with QKD. The secret sharing scheme produces, given some data to protect, secret shares to distribute on various servers. The distribution of the shares is protected using QKD. Moreover, the data are contiunously re-encrypted, by updating and distributing new secret shares to the servers.

This combination results in a very strong security for stored data. Thanks to the secret sharing scheme, it is not possible to recreate the secret data using a single server. This forces and eavesdropper to attack several servers. The re-encryption mechanism ensures that all servers have to be attacked at the same time!