[bitcoin-dev] Raise default datacarriersize to 220 byte or higher

["mbde@bitwatch.co" <mbde@bitwatch.co>]

Hi guys,

there are several ways to embed arbitrary data into the blockchain, and
this is used by several meta-protocols. Most protocols at this point use
OP_RETURN scripts for this.

To disincentivize the use of other and more harmful methods to embed
data into the chain, in particular via P2SH, I propose to raise the
default datacarriersize to 220 byte, so it becomes the "cheapest" way of
embedding data into the chain.

The following graph shows the relation between transaction sizes and
payload sizes: http://i.imgur.com/VAGZWBK.png

Embedding data with bare-multisig and P2SH can be cheaper in terms of
effective transaction size, compared to OP_RETURN with a payload limit
of 80 byte. Both methods of embedding data, via bare-multisig and P2SH,
were heavily used by the major two meta-protocols on top of Bitcoin:
Omni and Counterparty, but both protocols started to use OP_RETRUN data
embedding a long time ago.

However, currently token sends are usually done one by one, each with a
single transaction, and this is a heavy burden for the whole network,
e.g. when an exchange sends out withdrawals.

We have solutions for "multi-sends with multi-inputs" and also
considered moving destinations into the payload for token sends, but we
need more space, otherwise this solution is limited to very few recipients.

I therefore propose to raise the default datacarriersize to 220 byte or
higher and I'd be happy to provide a pull request doing so, if this gets
positive feedback.

- dexx