Monero — the popular privacy-oriented cryptocurrency — implemented bulletproofs into its protocol last Thursday following the Beryllium Bullet release that provided numerous updates including increasing the ring signature size to 11.
Bulletproofs are short non-interactive zero-knowledge proofs that enable much more efficient range proofs for anonymous transactions in Monero. There has been a substantial amount of excitement around their integration with the cryptocurrency, and the early results show drastic improvements in transaction size and fees.
Bulletproofs in Monero
Bulletproofs are an innovative cryptographic technique the improve privacy while drastically increasing efficiency. Monero employs Ring Confidential Transactions (RingCTs) that are an optimized form of ring signatures and are used to obfuscate transaction amounts. However, RingCTs require substantial size range proofs, which leads to much larger transaction sizes than other cryptocurrencies and subsequently cumbersome blockchain bloating.
Bulletproofs were proposed by the Stanford Applied Cryptography Group along with Greg Maxwell, Pieter Wuille, and Andrew Poelstra to increase the efficiency of the process by aggregating range proofs and collectively proving their validity.
Bulletproofs are similar to zk-SNARKs used in privacy-oriented cryptocurrency ZCash which are also founded on the concept of zero-knowledge proofs. However, Bulletproofs in Monero do not require the controversial trusted setup like in ZCash. Conversely, Bulletproofs are slower to verify than zk-SNARKs.
One of the most compelling improvements that Bulletproofs offer Monero are the dramatic increases in efficiency. Early testing of Bulletproofs in Monero led to 80 percent reductions in transaction sizes along with an 80 percent reduction in fees. An interesting development from such a sizeable drop in transaction size and fees is the eventual feasibility of micropayments for Monero that were previously not realistic.
Dramatic Improvements in Efficiency
According to Coinmetrics, the average Monero transaction size before the Bulletproof fork was 18.5kb and it is now at 3kb, a nearly 84 percent increase in transaction size efficiency. Further, the average transaction fees dropped from 60 cents to 2 cents, an improvement of more than 96 percent.
Those are enormous improvements and clearly validate the excitement surrounding the Bulletproofs implementation in Monero. BitInfoCharts also provides metrics analyzing the efficiency enhancements of the upgrade, and Digital Asset Research delivers some extensive analysis of Bulletproofs and their relationship to ZCash’s zk-SNARKs.
Monero consistently remains a primary option for cryptocurrency users seeking an advanced level of anonymity. With Bulletproofs, Monero has become a significantly more efficient network and implements a technology related to ZCash’s touted zk-SNARKs for providing the highest levels of privacy available in cryptocurrencies today.