Litecoin drops draft proposal for MimbleWimble implementation

Litecoin has published its long-awaited draft proposal for MimbleWimble implementation through Extension Blocks [EB] under the Litecoin Improvement Protocol [LIP] titled, LIP 2 & LIP 3.

This development was first revealed on Litecoin.com’s blog.

The first method, LIP 2, focuses on Extension blocks Implementation, which essentially allows not only MW, but an effective block size increase to be implemented without any change in the consensus rule to the network, as described by Bitcoin developer Johnson Lau.  The blog also revealed that discussions will be held around what the extension block size should be since the exact size is still up for debate as the “team was yet unsure at what it should be set at and whatever is chosen will be fixed once accepted.”

Activating the Soft fork

“Our primary motivation behind EB is to implement opt-in MimbleWimble. This is  something that is currently not possible through a traditional soft-fork because MimbleWimble is not script-based. However, there is also an opportunity to lay the groundwork to implement alternative proposals using EB as well.”

The Proposal mentions that the network will have to vote on whether the technology needs to be implemented or not. Network’s vote on the final code or to enable the soft fork would mean at least 75% approval from network participants. The fork will be activated one year after the implementation is released and “miners will be able to activate it early with a 75% signaling threshold.”

Extension Blocks to parallel alongside the main Litecoin blockchain

EB will run parallel to the LTC blockchain and in order to differentiate the EB chain from the parent, a new witness program will be implemented. This new witness will also ensure compatibility with existing rules. And this implementation will use Bech32 [addresses starting with lc1] due to its efficiency over legacy [L]and standard SegWit addresses [M], which would subsequently lower transaction fees in comparison.

LIP 3 is the one that deals with the actual MW proposal. Litecoin’s fungibility is hindered in several ways due to the transparent nature of the ledger. The proposal stated that MW was the “ideal protocol to implement for private transactions,” since it not only hides the amount being sent, but also because the transactional history is deleted from the ledger, thus increasing privacy by removing linked transactions and reducing blockchain size.

Plan to deal with quantum computing in the future

The post also revealed that the dev team has prepared a contingency plan in case quantum computing breaks the MW privacy commitment scheme or an attacker secretly mints new coin into existence. According to its proposal, the network can tun to a more secure solution and drop hidden transaction values just by “adding a switch commitment for Elagamal.”