Good morning Jeremy,
>
> Here's the day 6 post: https://rubin.io/bitcoin/2021/12/03/advent-6/, the topic is why smart contracts (in extended form) may be a critical precursor to securing Bitcoin's future rather than something we should do after making the base layer more robust.
*This* particular post seems to contain more polemic than actual content.
This is the first post I read of the series, so maybe it is just a "breather" post between content posts?
The series in general is intended to be a bit more on the approachable side than hardcore detail.
In any case, given the subject line, it seems a waste not to discuss the actual "smart" in "smart" contract...
Yeah maybe a better title would be "The Case for Enhanced Functionality in Bitcoin" -- it's not really about smart contracts per se, but the thing that people are calling smart contracts in the broader community. This gets down to prescriptive v.s. descriptive lingo and it's not really a debate I care much for :)
## Why would a "Smart" contract be "Smart"?
A "smart" contract is simply one that somehow self-enforces rather than requires a third party to enforce it.
It is "smart" because its execution is done automatically.
There are no automatic executing smart contracts on any platform I'm aware of. Bitcoin requires TX submission, same with Eth.
Enforcement and execution are different subjects.
Consider the humble HTLC.
<snip>
This is why the reticence of Bitcoin node operators to change the programming model is a welcome feature of the network.
Any change to the programming model risks the introduction of bugs to the underlying virtual machine that the Bitcoin network presents to contract makers.
And without that strong reticence, we risk utterly demolishing the basis of the "smart"ness of "smart" contracts --- if a "smart" contract cannot reliably be executed, it cannot self-enforce, and if it cannot self-enforce, it is no longer particularly "smart".
I don't think that anywhere in the post I advocated for playing fast and loose with the rules to introduce any sort of unreliability.
What I'm saying is more akin to we can actually improve the "hardware" that Bitcoin runs on to the extent that it actually does give us better ability to adjudicate the transfers of value, and we should absolutely and aggressively pursue that rather than keeping Bitcoin running on a set mechanisms that are insufficient to reach the scale, privacy, self custody, and decentralization goals we have.
## The N-of-N Rule
What is a "contract", anyway?
A "contract" is an agreement between two or more parties.
You do not make a contract to yourself, since (we assume) you are completely a single unit (in practice, humans are internally divided into smaller compute modules with slightly different incentives (note: I did not get this information by *personally* dissecting the brains of any humans), hence the "we assume").
Thus, a contract must by necessity require N participants
This is getting too pedantic about contracts. If you want to go there, you're also missing "consideration".
Smart Contracts are really just programs. And you absolutely can enter smart contracts with yourself solely, for example, Vaults (as covered in day 10) are an example where you form a contract where you are intended to be the only party.
You could make the claim that a vault is just an open contract between you and some future would be hacker, but the intent is that the contract is there to just safeguard you and those terms should mostly never execute. + you usually want to define contract participants as not universally quantified...
This is of interest since in a reliability perspective, we often accept k-of-n.
<snip>
But with an N-of-N, *you* are a participant and your input is necessary for the execution of the smart contract, thus you can be *personally* assured that the smart contract *will* be executed faithfully.
Yes I agree that N-N or K-N have uses -- Sapio is designed to work with arbitrary thresholds in lieu of CTV/other covenant proposals which can be used to emulate arbitrary business logic :)
However, the benefit of the contracts without that is non-interactivity of sending. Having everyone online is a major obstacle for things like decentralized coordination free mining pools (kinda, the whole coordination free part). So if you just say "always do N-of-N" you basically lose the entire thread of"smart contract capabilities improving the four pillars (covered in earlier posts) which solidifies bitcoin's adjudication of transfers of value.