Improving the Efficiency of a Blockchain-Based Confidential Registered e-Delivery Protocol

Abstract

[eng] Security protocols based on blockchain technology need to achieve some relevant features to spread their acceptance. In this paper we present a set of implementation techniques to enhance the efficiency and the operational cost of such protocols. We have recently presented a powerful protocol for confidential registered e-deliveries of data [2] that fulfills the security requirements for this service thanks to the use of blockchain technologies. However, the efficiency and the execution costs could reduce its viability. In this paper we present an improvement of this protocol acting in three different aspects of the protocol: the way the encrypted data is stored, now we use an off-chain storing scheme; the cryptosystem used, making it possible to use shorter keys with the same security level; and the implementation of the smart contracts, where more efficient functions are used allowing lower costs in the creation of the deliveries. The paper has a description of the protocol with the new improvements. Also we have implemented, tested and compared the new proposal with the original one, showing how the costs have been reduced significantly.