Replying to Avatar TheKayman

The fees are the filter argument does not address the mempool issue that this change to op_return brings.

Because core 30 nodes will accept and relay 100kb files by default, this allows for files to be sent across the p2p network without having to get this transaction mined.

Criminals / bad actors can exploit this by relaying illegal data to their buddy on the other side of the world, anonymously and for free because this is all happening at the mempool level.

Yes, eventually after a period of time of this transaction not being mined it will be dropped from the node’s mempool, but by this point that illegal file has already been relayed to other bad actors.

In short: the removal of op_return filters in core 30 software creates infrastructure for an extremely effective, anonymous and free data relay / sharing service that will be exploited by criminals with illegal files.

This is not me being a purist saying “this is immoral”. This is me saying “this introduces a legitimate attack vector that governments and the powers at be who want to see bitcoin fail WILL use”.
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Ahi 3mo ago 💬 2

You can do that now placing the data in SegWit/Taproot witness and it will be relayed.

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TheKayman 3mo ago

That’s true, but there’s a difference between people using an exploit that is not natively supported vs using op_return which is a feature with the purpose to allow arbitrary data.

By increasing the op_return limit you are now signalling that relaying large blobs of continuous data is a feature supported by the network. In contrast, shoving split up chunks of data into the witness section where it is not designed to be is not an intended use of the network.

The argument is that: now relaying large continuous chunks of data is natively supported, any legal/regulatory plausible deniability is gone.

From a technical standpoint this change also makes it easier for bad actors / criminals as they don’t have to split their files into multiple chunks.

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Ahi 3mo ago 💬 3

Is there some rule I don't get? (Likely) You can put in 100k vbytes now and you don't need to split them?

https://bitcoin.stackexchange.com/questions/117277/what-is-the-maximum-size-transaction-that-will-be-relayed-by-bitcoin-nodes-using?utm_source=chatgpt.com

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TheKayman 3mo ago

The 100k vbytes refers to the total size of the transaction including witness data, headers, the inputs and outputs, etc. For inscriptions spammers use the witness data aspect of the transaction.

From my understanding, each input has its own witness field, which can carry only a limited amount of data. To include larger files, the data must be split across multiple inputs and/or multiple transactions. The total transaction size cannot exceed100k vbytes.

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Ahi 3mo ago 💬 1

How much bigger percent wise can one input in the mempool be after this? Is this a concern?

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calle 3mo ago

0%

max block size is 4mb since 2017.

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TheKayman 3mo ago

There is no size increase for the total transaction (still 100k vbytes), and so there is no size increase to the inputs. The change is changing how much data in the op_return part of the transaction nodes will relay. The change means your op_return data can take up the entire 100k vbytes and core 30 nodes will still relay it by default. Prior to core 30 nodes would only relay transactions with a max of 80 bytes op_return data by default.

The change basically means the bitcoin p2p network supports transactions that are completely arbitrary data or spam.

The concern comes from whether you think nodes relaying 100kb files, uploaded anonymously for free could be an attack vector for bad actors.