Thin Blocks technology supported by Classic and BU: making block transmission easier

Today, the foreign community reported the latest experimental progress of Thin Blocks. On the Bitcoin Unlimited 0.12 (BU, see Note 1) client that supports this technology, high-speed transmission of large blocks was achieved. For example, block #400152 was first mined by the BTCC mining pool in China and was discovered by Blockchain.Info at 16:46:31 on 2016-02-26. But it was not transmitted to the author's node in Germany until 49 seconds later. However, in the BU client that supports Thin Blocks, the whole process took less than 1.5 seconds, that is, all operations of request, reception, assembly and transmission were completed, allowing neighboring BU nodes to synchronize quickly. The original size of block #400152 is 956.21KB, while the size of the transmitted Thin Block is only 92.64KB. That is, the block size is almost reduced by 10 times. Blocks #400154 (949KB) and #400160 (934.2KB) are even more significant, with bandwidth requirements for thin blocks reduced by 39.14 times and 48.99 times respectively. The experimental node runs on a home network with a bandwidth of only DSL 2.5mbit/s. The node has a total of 18 external connections, of which 6 are BU nodes. Since block transmission time has a considerable impact on the income of mining pools, this is also one of the main reasons why many mining pools are reluctant to upgrade to larger block sizes. It is believed that development and experiments in this area will have an important positive impact on the expansion and upgrade of Bitcoin blocks.

Note:

(1) Bitcoin Unlimited is a Bitcoin client launched last year by developers including Peter R. Its feature is that the block limit control is left to the user rather than being determined by the developer or mining pool.

(2) Thin Blocks technology can be found in the Classic roadmap and is expected to be implemented in the second phase of Classic.