Subject: Re: [bitcoin-dev] Compressed Bitcoin Transactions

From: Fabian <[email-masked]>
Date: Fri, 01 Sep 2023 10:43:26 +0000

Hi Tom,

I realized I simplified my message a bit too much. Of course an index of the UTXO set would also need a height, so I rather meant some kind of composite reference I guess. An index alone might be enough if a height has been pre-agreed which could still be compatible with the use-cases you might have in mind, this might be very interesting in combination with assumeutxo. Otherwise a short hash could be used but then I also think your current scheme might be more space efficient than this.

Fabian
------- Original Message -------
On Friday, September 1st, 2023 at 12:24 PM, Fabian <[email-masked]> wrote:

> Hi Tom,
>
> without having gone into the details yet, thanks for the great effort you have put into this research and implementation already!
>
>> The bulk of our size savings come from replacing the prevout of each input by a block height and index.
>
> Have you also considered using just an index from a sorted UTXO set instead? The potential additional space saving might be minor but this would make the scheme compatible with pruning. I had this on my list as a future research topic but didn't get around to it yet.
>
> Thanks,
> Fabian
> ------- Original Message -------
> On Thursday, August 31st, 2023 at 11:30 PM, Tom Briar via bitcoin-dev <[email-masked]> wrote:
>
>> Hey everyone,
>>
>> I've been working on a way to compress bitcoin transactions for transmission throughsteganography, satellite broadcasting,
>> and other low bandwidth channels with high CPU availability on decompression.
>>
>> [compressed_transactions.md](https://github.com/TomBriar/bitcoin/blob/2023-05--tx-compression/doc/compressed_transactions.md)
>>
>> In the document I describe a compression schema that's tailored for the most common transactions single parties are likely to make.
>> In every case it falls back such that no transaction will become malformed or corrupted.
>> Here's a PR for implementing this schema.
>>
>> [2023 05 tx compression](https://github.com/TomBriar/bitcoin/pull/3)
>> Thanks-
>> Tom.