Allowing light weight verifiers to download transactions directly off the blockchain


#1

Hi BlockCerts community,

I’ve been playing around with an spv client (https://bitcoinj.github.io) to see if it’s possible to directly download transactions off the blockchain without running a full node or relying on a third party services like blockchain.info. From browsing the web, I soon realized that most nodes on the network only allow you to download blocks and do not support direct transaction queries. Although I was not able to directly download transactions off the blockchain with only the transaction IDs, I was successful when I knew the block hash. I would like to know what people think about including the block hash in certificates to allow light weight verifiers to lose their dependence on third party services.

Please correct me if I have stated something false.

Thanks

Noah


#2

This is a great point Noah.

In fact, we could use tx refs instead of transaction ids. This includes the chain code, block height, and block position. The BIP hasn’t been merged yet, but here’s the PR: https://github.com/bitcoin/bips/pull/555

We used tx refs in the BTCR DID method spec. Some context and libraries demonstrating this:


#3

Thanks Kim! I will take a look.