In Italy every citizen has an electronic ID card that contains a private key and can sign challenges. It also has state-signed credentials/certificates that bind the public key to info about the citizen (date of birth etc).
You can do this: when you want to log into a service, the service provider gives you a fresh challenge C, bound to that service/session. You sign the challenge, and then generate a zkp of the fact that:
1. you have the signed challenge C with a certain public key P
2. you have a state-signed credential/certificate that binds P with a person with birth date BD
3. current date - BD > 18 years
4. optionally, you derived a per-service nullifier, e.g. from the card/credential secret, the service origin and a time bucket, so the service can rate-limit abuse without getting a global cross-site identifier
You send the proof to the service provider, that verifies it, and learns nothing about you (except for the fact that you're of age).
An adult can of course give away the card/PIN, but you need to have it physically to sign fresh challenges, so it cannot be passed around as easily as a bearer token. Moreover he loses access to his actual ID, which is required for other services.
yeah, hashcash is a very neat idea! but had problems like: how do you determine the threshold for the amount of work to be proven? there are values that makes it too expensive for a well intentioned human, and not enough for a bad intentioned spammer... moreover, it would induce economies of scale like it happens in bitcoin mining (spammers would invest in ASICs etc.) Signatures, on the other hand, allow to cheaply leverage other forms of "capital" (digital identity, github activity)
Could this be addressed with cryptography, digital ids and signatures? Imagine it were possible to add a signature that proves that I own some "human" identity (like a national id), or that I possess some scarce resource (like a github account with some level of activity) and that today I sent no more that 20 emails. If I want to conceal my identity, I can use zero knowledge proofs. If you don't sign this way, or if your daily email counter exceeds 100, your mail ends up as spam.
Farcaster is doing it (allowing posting, upvoting etc) with a pragmatic architecture with different degrees of decentralization (identity onchain, posts on a p2p storage à la bittorrent), and it's going pretty fine... https://warpcast.com/
ether, Ethereum's native token, is required to pay for computation on a computer with peculiar properties (publicly visible, unmodifiable, unstoppable code, uncensorable interaction). If somebody finds that useful, he will need ethers, and you will be able to sell them yours. How would he be a (greater) fool?
Digital scarcity seems like a fundamental concept also in the digital realm. Consider games: if you only have a certain number of weapons, lives, or limited time, isn't that digital scarcity? If you play capture the flag, the fact that there is only one flag, and only one team can "own" it at any one time, isn't that digital scarcity? Aren't the points you get from sweating arbitrarily "scarce"? Or isn't the first position a ranking "scarce"? It seems to me that scarcity is at the heart of many fundamental social mechanics, be they physical or digital.
Couldn't blockchains offer some new tools to tackle the problem? Imagine for instance wanting to create some incentives by distributing the value of correctly tracking an item to the actors of the supply chain, with some rule like "once the item is sold, part of the revenue gets distributed to all the actors that contributed to the tracking". Wouldn't smart contracts render this simpler to implement, since code is visible by all actors and guaranteed to be executed?
Sidechains have different security properties. You probably know xdai (https://www.xdaichain.com/), where you can transact tokens that "wrap" dais from Ethereum mainnet. The sidechain is secured by a proof of authority consensus, where you require a fraction of validators to behave honestly. If a certain number of validators collude, they can do nasty things, such as censoring transactions from a certain address, or keeping the chain from making progress. This is not possible in a rollup, either optimistic or zk, because any single user can always commit a batch or report fraud on L1, so you just need a single honest actor for things to work.
In self sovereign identity systems based on verifiable claims, attributes are attested through signed claims on digital identifiers that the user control (e.g. a public key). Blockchains here are the most effective mean to implement claim revocation: if someone who produced a claim wants to revoke it, he writes that on a blockchain.
One thing that comes to mind is reversible computing. (https://en.wikipedia.org/wiki/Reversible_computing). When computation is irreversible (as is the case for all our current information elaboration systems and substrates), it is bounded below in the energy that dissipates. The bound is quantified by the Landauer principle, and has to do with the entropy involved in "forgetting" the previous states. If a computation process is reversible, it doesn't incur in such limit. One can maybe imagine time crystals concocted to carry out useful computation, spending no energy in the process.
I guess that that's what happened, and what's happening everyday... Newton action at a distance wasn't convincing enough, so others sought other, "deeper" explanations, among which most notable is of course general relativity. (And it's probably noteworthy that, from an "instrumental" point of view, its benefits were initially marginal...) The difference to me is between saying "the explanatory power of this current theory can (and will eventually) be outdone" and "being able to explain is a dimension of no importance in a scientific theory". Maybe that is Chomsky's concern, even though this instrumentalist attitude is far from new or unknown (think of Copenhagen (lack of) interpretation of quantum mechanics, and its (in)famous motto: "Shut up and calculate"!) If you are interested in this line of reasoning, I found David Deutsch ("The beginning of infinity") and Karl Popper ("Conjectures and Refutations") two passionate (and opinionated) voices!
Claiming there's no difference between prediction and understanding reminds me to what philosophers of science call "instrumentalism": theories are only to be judged by how well they work in predicting facts. But imagine a world in which Newton, instead of formulating the law of universal gravitation and the laws of motion, built a complex machine that, given the relative positions of a set of planets, could work out their subsequent trajectories, with astonishing precision. Nobody would be able to explain why it works in any "deeper" way. Would that world be undistinguishable by ours? If anything, would have Einstein had the same chances of devising general relativity? And Schwarzschild of deriving from it that black holes should exist? Doesn't the fact that we care whether black holes exist, despite how little they admittedly influence the set of mundane phenomena we observe everyday, imply that this world is distinguishably different from that with the accurate, hypothetical Newton black box?
And since human nature limits the size of group that can work together, the only way I can imagine for larger groups to avoid tree structure would be to have no structure: to have each group actually be independent, and to work together the way components of a market economy do.
That might be worth exploring. I suspect there are already some highly partitionable businesses that lean this way. But
I don't know any technology companies that have done it.
Highlight: "With these monosynths you can get inhumanly fast (or slow) complex pulses that phase, bounce off each other and interlock in ways that no human ensemble could ever achieve, while retaining the live performance element in all the other areas".
To me, the example of one of the most thrilling potentialities of computers and informatics.
"The Beginning of Infinity", from David Deutsch, in which evolution, Popper epistemology and theory of computation blend into a world view fruitful of thrilling perspectives for humanity. To me, as mind blowing as anything can ever be.
You can do this: when you want to log into a service, the service provider gives you a fresh challenge C, bound to that service/session. You sign the challenge, and then generate a zkp of the fact that:
1. you have the signed challenge C with a certain public key P 2. you have a state-signed credential/certificate that binds P with a person with birth date BD 3. current date - BD > 18 years 4. optionally, you derived a per-service nullifier, e.g. from the card/credential secret, the service origin and a time bucket, so the service can rate-limit abuse without getting a global cross-site identifier
You send the proof to the service provider, that verifies it, and learns nothing about you (except for the fact that you're of age).
An adult can of course give away the card/PIN, but you need to have it physically to sign fresh challenges, so it cannot be passed around as easily as a bearer token. Moreover he loses access to his actual ID, which is required for other services.