Fractional Reservation Based Mempool Processing in Blockchains

A massive traffic events that impact all the nodes in the distributed system may cause a Denial of Service (DoS). Managing DoS attacks is even harder in peer-to-peer projects because of multiple equal in rights nodes (miners or maintainers) that communicate across the globe to secure the network. In most blockchains, users can send transactions. Moreover, as a systems throughput is limited, the ability to send transactions should be limited in some honest and transparent way. Otherwise, the pool of unconfirmed (pending) transactions mempool could be overloaded, and it may cause DoS. In Bitcoin, users pay a fee for each transaction to address this issue. Steem.io introduced an alternative approach based on the fractional reservation of the blockchain block space. This approach is an adaptation of similar ones from the network routing and banking systems. The block space fractional reservation for blockchains in terms of a score function is introduced in this paper. Authors made a private blockchain project demo on Exonum framework. The score function influences only on mempool processing, and other blockchains can also make use of it.