Proposal for Syncing Channel Updates
An update was suggested to include channel update timestamps to the channel range queries, the reply_channel_range will now include 4 bytes of a timestamp and the query_short_channel_ids will include a flag that is set to 1 if the node should send back a channel announcement and the updates, and would otherwise send just the updates.
blocksonly mode - how to reduce bandwidth usage by 88%

Running a Bitcoin node is the healthiest way to contribute to the Bitcoin Network but in the past couple of years it has become very expensive to run one both in storage and bandwidth.

A process called blocksonly mode was introduced in Bitcoin 0.12 with the aim of helping Bitcoin Node owners save a hefty amount of bandwidth and still contribute to the network. blocksonly mode allows nodes to stop requesting, relaying and listening for transactions until they are bundled up in a block.

Both-side funded channels

Cezary Dziemian raised a question on lightning-dev regarding channel funding:

About weak ago I talked with Christian Decker, and he told me, that there is plan to implement possibility of both-side funding channels. He told me, that I will be able (for example) to pay 100 sat for peer if he agreed to put some of his funds to channel. Everything in single, trustless transaction.

Do I understand this correctly? And if so, do you have any predictions when it could be implemented?

Bitcoin Encrypted Communication (BIP151) Overhaul

On of the pros of Bitcoin since its birth is that it’s a public ledger, anyone is allowed to send and receive payments and data on the Blockchain. However, Bitcoin’s network does not provide a way of encrypting communication between nodes, which allows manipulation of data, mass surveillance and analysis of its users.

Although encrypted communication is currently a possibility with VPNs, TOR or other mechanisms, it is not easy for the average user to setup such a connection. There is BIP draft called BIP151 that aims to add encrypted communication to Bitcoin’s network and which currently seems implemented only by Armory.

Jonas Schnelli presented an overhauled version for BIP 151 with some major changes:

On Lightning Nodes Centrality

Lightning Network is one of the key upcoming technologies that will change Bitcoin for the better, it’s a network of nodes with channels between these nodes that process payments and transactions “off-chain”, to keep only the few important transactions on-chain and decrease the load on the blockchain and the time it takes to send a transaction.

However there is a potential for node centrality in the lightning network, the main issue being that some nodes might end up functioning like banks, processing the bulk of these transactions. Developer Kulpreet Singh set out to measure the centrality of nodes in the Lightning network.

Building a Bitcoin API and Query System

Currently, in order to get information on a Bitcoin block or transaction, one has to sync his node with other nodes in a P2P network to be able to query the block for the information required.

Sumit Lahiri presented a BIP proposal to build an API that enables users to “easily query Bitcoin blocks and transactions” without having to sync with other nodes on the network.

One of the issues with the proposal is that light clients like Electrum, Spruned and Bitcore offer most if not all of the functionalities because the “servers are designed to quickly answer the query of light client wallets”.

Witness Serialization in PSBT Non-witness UTXOs

Pieter Wuille made some comments regarding the serialization of non-witness UTXOs in the recenlty proposed BIP174:

BIP174 currently specifies that non-witness UTXOs (the transactions being spent by non-witness inputs) should be serialized in network format.

I believe there are two issues with this.

Smaller Testnet Blocks

Currently bitcoin’s testnet mining is done by mining the entire mempool in every block, this can be relatively annoying to anyone doing development that depends on a fee market like fee adjusting or transaction merging. Recently a developer called on the bitcoin-dev mailing list for the maxBlockWeight of Bitcoin’s testnet to be changed to something less than the entire mempool to help wallet developers in testing. This is a reasonable suggestion as some mainnet wallets have to deal with fee-related problems like stuck transactions and fee bumping. The suggestion is very early but looks promising, we’ll be watching the mailing list for any new updates.