A Quantum Assisted Secure Client-Centric Polyvalent Blockchain Architecture for Smart Cities

We propose a quantum assisted secure distributed ledger system that is client centric and polyvalent. The multiple attribute lock encryption (MALE) provides asymmetric key encryption to protect the data. The keys are of high randomness as they are generated via the simulation of a quantum walk. Quantum random walkers on a circle structure have been shown to be an efficient pseudo-random number generator. On top of the quantum random walker, we apply the quantum key distribution (QKD) protocol to avoid the double spending problem and to serve as a seed provider for the quantum walk. We further design the key chain update protocol with the help of MALE mechanism after each data access. Both QKD and quantum random walker can be efficiently simulated with current classical computation and near-term quantum technologies. Potential applications of proposed work in smart-city context are briefly discussed as well.