Since its creation in 2009, Bitcoin has always adopted a so -called ossified approach. In other words, this means that it tends to limit developments in order to keep its safety. This does not prevent the community from debating potential developments in the protocol. In recent days, a new controversy is agitating the community: the deletion of the limit of 80 bytes for data stored via the OP_Preturn function. This modification, although in advance at first glance, generates debates on the very identity of Bitcoin.
- Bitcoin Core surprised the community by removing the limit of 80 bytes from the OP_TRETurn function in its next version, thus overwhelming the traditional identity of the protocol.
- This change could transform Bitcoin into a more versatile platform, but arouses fears about an increased risk of centralization and diversion of its original mission.
Op_return: a tool at the heart of controversies
First of all, let us remember that Bitcoin’s programmability is done via the langage Script. This has native instructions, called Opcodes.
Among them, we find the function OP_RETURNwhich was introduced in 2014. This one Allows you to save data on the Bitcoin blockchainlike hashs of documents or messages.
Initially limited to 40 bytesits size was Increased to 80 bytes in 2015. A voluntarily reduced size to avoid the abusive storage of non -financial data.
However, in 2023, the Ordinal inscriptions bypassed this limit by taking advantage of Taproot.
Faced with this situation, some observers simply offer Remove the limit of 80 bytes from op_return. In practice, the deletion of this limit would allow transactions that store up to 4 MB of data. Namely the maximum size for a Bitcoin block.
As explained Greg Sandersone of the defenders of the abolition of this limit, it is not a change in consensus, but an adaptation of the transaction relay rules. Thus, minors would remain free to set their own limits.
Bitcoin Core removes the limit of the op_return
Against all expectations, even though no consensus around this question has been found, the Bitcoin Core client developers decided to take the lead.
Thus, Bitcoin Core announced that they removed the limit of OP_return in the customer’s next version.
“The next version of Bitcoin Core will relay and minera, by default, the transactions whose OP_Preturn outputs exceed 80 bytes and will allow any number of these outings. The ceiling in force for a long time, which was originally a gentle signal indicating that the block space had to be used sparingly for the data of non -paying publication, has no use. »»
On the one hand, Bitcoin Core no longer sees the interest of such a limitbecause it is already bypassed by private minors, specialized services or even via Taproot. Which, according to them, has another consequence, namely that users find alternative solutions that pollute UTXO more. As Greg Sanders, Bitcoin Core developer explains:
“The current limit has become obsolete since Taproot allows you to store much more via ordinal inscriptions. »»
Indeed, according to Bitcoin Core, 30 % of the blocks currently undermined on Bitcoin already bypass this limit via Taproot.
In addition, without strict limit, Bitcoin could accommodate emerging use cases: simplified intelligent contracts, light NFT, or horodatages of legal documents.
-The fears of opponents
Obviously, the abolition of this limit is not to everyone’s taste. Thus, many Bitcoin developers and actors have made their voices heard.
Pour Luke dashjrthis could cause a drift of the original Bitcoin mission.
“It will transform our blockchain into a database of data. »»
For him, delete the limit op_return returns to encourage spamillicit content and increased centralization.
Indeed, transactions which contain more data also offer more costs to the minor that will validate it. As a result, minors are encouraged to include large -rate transactions and could prioritize data to the detriment of conventional monetary transfers. Which would distance Bitcoin from its function of simple digital currency.
Finally, detractors fear that it has a Impact on network nodes. Indeed, who says more data in transactions, says more data to store for nodes. This would make the operation of a complete node more expensive, risking centralizing the network in the hands of a handful of actors.
A choice based on minors
In fact, it is the minors who will have the last word on this affair. Indeed, the abolition of the OP_return limit in Bitcoin Core imposes nothing on minors.
These can always set a maximum size via their own policies.
In addition, the size of the blocks remains capped at around 4 MB thanks to the existing consensus. Even with unlimited op_return, a minor could not include a 5 MB transaction without the block being rejected by the network.
Finally, the emergence of alternative customers such as Bitcoin Knots gives an alternative to the community. Users anxious to preserve the historical limit can migrate to this customer, while those who are favorable can remain on Bitcoin Core.
Op_return: a wider ideological conflict on Bitcoin
Behind this technical battle hides a Old debate like Bitcoin. On the one hand, the purists consider Bitcoin as an anti -sister monetary system which must remain minimalist.
On the other, expansionists see it as a global platform capable of competing with Ethereum or Solana.
The former invoke the vision of Satoshi Nakamoto, whose white paper mentioned no use outside payments. The latter retort that Bitcoin must innovate to survive, citing the Lightning Network as an example of successful evolution.
Unsurprisingly, Op_return is not the only Opcode to debate. Indeed, of Many entities, including Starkware, campaign for the reintroduction of OP_CAT. An OPCODE that has been removed for security concerns, but which would allow the emergence of L2 on Bitcoin.
