timestamp – Can Taproot be used to commit arbitrary knowledge to chain with none further footprint?
Sure, you possibly can decide to knowledge this manner, however there may be nothing particular about Taproot right here.
The Pay-to-Contract development used to tweak the foundation key in Taproot is usually usable, and has in actual fact been used for precisely this goal. In reality, it is without doubt one of the mechanisms utilized in OpenTimestamps to decide to timestamped knowledge (together with a variant sign-to-contract which makes a signature decide to knowledge fairly than a public key). It is usually utilized in Blockstream’s Liquid pegin mechanism, the place transfers from Bitcoin to Liquid pay to an deal with derived utilizing a tweaked key of the federation, which commits to the switch info.
In reality, utilizing an extra leaf in Taproot for that is overkill, and would inevitably enhance the depth within the Merkle tree for at the least one different leaf – leading to elevated spending value. Simply utilizing pay-to-contract or sign-to-contract immediately on one of many public keys concerned might be carried out with zero value to on-chain spending insurance policies.
Would this not considerably scale back the price of companies like coloured cash, timestamping companies, and many others, which commit their knowledge immediately onto the chain?
Respectable timestamping companies already use higher strategies.
For coloured cash it relies upon whether or not they simply want timestamping or precise publication of information. My understanding is that it is typically the latter (as in any other case, they want one other censorship-resistant channel to switch the precise knowledge, which might then most likely be used immediately).