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The Runes protocol is the latest development in the explosion of new tokenization models that have appeared on top of bitcoin’s base layer over the past year or two.
At a time when mostly useless meme coins are gaining massive attention in the cryptocurrency market, the Runes protocol allows a new way of issuing fungible tokens on bitcoin which offers improvements over the somewhat successful BRC-20 standard. Launched on the fourth bitcoin halving at block 840,000, the Runes protocol led to a massive spike in transaction fees that allowed miners to earn more revenue after the halving of the block reward had occurred, than they were earning prior to the event.
Let’s take a closer look at the Runes protocol on bitcoin and whether it has a chance at standing the test of time as the preferred method for issuing fungible tokens on the world’s most valuable blockchain.
Token Issuance On Bitcoin
Although tokenization did not really come to prominence until the initial coin offering (ICO) bubble on Ethereum in 2017, the reality is the original forms of cryptocurrency token issuance were founded on bitcoin.
The colored coins concept, which was the original form of tokenization on bitcoin, goes back as far as 2012, and a variety of protocols for issuing both fungible and non-fungible tokens (NFTs) on top of bitcoin have developed over the years. Two of the most prominent protocols were Mastercoin (now called Omni) and Counterparty. In fact, Tether USD (USDT), which is by far the largest and most popular stablecoin in the world, was originally issued via Omni.
Despite the long history of tokenization on bitcoin, the world’s most valuable blockchain only began competing with other layer-one cryptocurrency networks in terms of token issuance in earnest last year with the creation of Ordinals. According to Cryptoslam, bitcoin is now a main hub of NFT activity, thanks to this development.
More recently, the BRC-20 token standard was built on top of Ordinals as a way of issuing fungible tokens on bitcoin. Additionally, Taproot Assets and RGB have been developed as additional options for issuing tokens on top of bitcoin and transferring them via the Lightning Network.
While many bitcoin maximalists are against the idea of alternative crypto assets in general, the reality is many people love gambling on small-cap meme coins — even if there’s no true, long-term valuation thesis behind them. Additionally, the most successful form of tokenization, stablecoins, has proven utility as the preferred medium of exchange in the cryptocurrency market. USDT alone currently sits at a roughly $110 billion market cap.
Due to the clear demand for additional tokens found throughout the cryptocurrency space, it makes sense for those who view bitcoin as the cryptocurrency market’s base money to build protocols for tokenization directly on top of the bitcoin network — removing the need for alternative layer-one blockchains for this particular use case.
Enter Bitcoin Runes
The Runes protocol is the latest addition to the ways in which new tokens can be issued on top of bitcoin. This new protocol was developed by Casey Rodarmor, who was also the bitcoin developer behind the Ordinals phenomenon. Compared to BRC-20s, Runes is a much more practical and efficient protocol. This should not come as a shock because BRC-20 is a rather crude protocol that was thrown together quickly as more of a proof-of-concept than anything else.
To be clear, the focus of Runes is on fungible tokens rather than NFTs, although Rodarmor admittedly does not see much value in these kinds of tokens. “I’m highly skeptical of ‘serious’ tokens, but Runes is without a doubt a ‘serious’ token protocol,” Rodarmor posted on X.
The main way Runes offers an improvement in efficiency is by not bloating bitcoin’s set of unspent transaction outputs (UTXOs), as bitcoin’s OP_RETURN functionality is used to store token data more efficiently. Notably, OP_RETURN outputs do not need to be tracked and stored by bitcoin full nodes, as they’re provably unspendable.
According to data from Glassnode, bitcoin’s UTXO set skyrocketed following the launch of the BTC-20 token standard in March 2023. In addition to increasing data storage requirements for bitcoin full nodes, basing BRC-20 tokens on Ordinals also has the side effect of increasing costs for users due to the need for more block space to be used in transactions related to the tokens than is the case with Runes.
Much like Taproot Assets and RGB, Runes can also be transferred over the Lightning Network, which is yet another efficiency gain over BRC-20s. However, unlike Taproot Assets and RGB, Runes does store data related to the tokens directly on the blockchain. That said, Runes does not have its own native token, which is the case with Omni and Counterparty.
How Bitcoin Runes Work Technically
Runes work by sending OP_RETURN transactions on the bitcoin network. An OP_RETURN is a special opcode that allows users to attach up to 80 bytes of additional data to a particular transaction.
The OP_RETURN opcode is used for creating, minting, transferring, and burning tokens in the Runes protocol. These OP_RETURN transactions in the Runes protocol are known as Runestones. Additionally, Runes are stored in specific outputs in the UTXO set.
How Bitcoin Runes Are Created
To create Bitcoin Runes, data must first be embedded into an OP_RETURN transaction. This process is known as etching. Here is the info that can be included in the OP_RETURN transaction associated with the new tokens:
- Rune: This is the name of the token. It can contain between one and 28 characters; however, the only valid characters are capital A-Z and spaces represented by the “•” character. If a name is not chosen, a name will be assigned based on the transaction’s data.
- Divisibility: This is a number that represents the number of decimal places that exists for the token’s divisibility.
- Currency Symbol: This is the official currency symbol for the token that should be displayed following a displayed token amount. The default is “¤”.
- Premine: Creators of Runes can use this field to reserve a specific amount of the token for themselves.
- Open Mint Terms: The token creator can set terms of an open mint if they’d like to allow the minting of the token supply to be public and open to others. The terms to set for an open mint include mint cap, amount per mint transaction, start block height, end block height, start block offset, and end block offset.
Once a Rune has been etched, it then must be minted based on the terms outlined in the etching to come into existence. To mint Runes, a user must create an OP_RETURN transaction that includes the Rune ID in the Mint field and the associated output to assign the tokens via the Pointer field. The Rune ID is based on the block height and transaction index related to the Rune’s original etching. If an output is not provided in the OP_RETURN, then the Runes will be assigned to the first non-OP_RETURN output in the minting transaction.
As a side note, the Rune field was a major reason for the massive fee spike on the bitcoin network when the Runes protocol originally launched, as users were attempting to outbid each other for the rights to etch Runes with specific, noteworthy names, or especially for the “claim-to-fame factor” of being included in block 840,000
Transferring Bitcoin Runes
The process for transferring Runes is not too dissimilar from creating new Runes in the first place. An OP_RETURN transaction is, again, all that is needed to transfer Runes; however, the data that must be entered into the OP_RETURN field for this type of Runestones message is a little bit different than it is with etching or minting.
The only three pieces of information needed to transfer Runes via Runestones are the Rune ID, the amount to transfer, and the output where the Runes should be transferred. Again, if a destination output is not provided, then the Runes will be assigned to the first non-OP_RETURN output in the associated transaction. In fact, if an output with some Runes associated with it is sent to a new bitcoin address without an associated Runestones message, then the default action is for 100% of the Runes associated with the former output to be assigned to the first non-OP_RETURN output in the transaction.
Burning Bitcoin Runes
There is also a process for burning Runes via Runestones. This is done by choosing a provably unspendable OP_RETURN output as the recipient of the Runes.
Additionally, Runestones with errors in them will burn the associated Runes. These are known as cenotaphs. Malformed etchings will also generate Runes that are unmintable. Cenotaphs can also be used as an upgrade mechanism for the Runes protocol.
Those who wish to dive deeper can read the full Runes specification for the Ord client.
The Future Of Bitcoin Runes And Tokens On Bitcoin
For now, the future of tokenization on bitcoin is rather unclear, as several different, competing protocols are either already live or in development, offering this same functionality. It’s unclear if the Runes protocol will stand the test of time, but it’s clear that there is demand for gambling on these sorts of low-value, meme-based tokens for now. Additionally, the Runes protocol itself could be extended and evolved to enable new use cases.
Over the long term, it may be more efficient for this sort of activity to take place on Bitcoin Layer 2 networks like Lorenzo App Chain. There’s also the potential for these types of tokens to be originally created on bitcoin’s base blockchain before then being ported up to secondary network layers for transfers, as use cases in decentralized finance (DeFi), and other functionality.
That said, the Runes protocol has proven to be another source of increased transaction revenue for miners over the short term, and much more of that kind of activity will be needed over the long term to ensure the viability of the network. When Runes are combined with Ordinals, Bitcoin L2s, and other recent developments, it seems that there will be plenty of activity on bitcoin to incentivize miners to keep the network secure. Whether it’s through Runes or some other protocol, there is a clear demand for alternative cryptocurrency assets built directly on top of bitcoin.