Community at HN does not like Wolfram; on the issue of Oracles/Human input @ cryptosystems, he is spot on on the solution as he has had first hand experience with Wolfram|Alpha being used as an oracle by smart contracts (the whole post is amazing btw):
And so it is with bitcoin, Ethereum, etc. The idea is that some particular thing that happened (“X paid Y such-and-such” or whatever) is shared and recorded in so many places that there can’t be any doubt about it. Yes, it’s in principle possible that all the few thousand places that actually participate in something like bitcoin today could collude to give a fake result. But the idea is that it’s like with gas molecules in a room: the probability is inconceivably small. (As it happens, my Principle of Computational Equivalence suggests that there’s more than an analogy with the gas molecules, and that actually the underlying principles at work are basically exactly the same. And, yes, there are lots of interesting technical details about the operation of distributed blockchain ledgers, distributed consensus protocols, etc., but I’m not going to get into them here.)
It’s popular these days to talk about “smart contracts”. When I’ve been talking about “computational contracts” I mean contracts that can be expressed computationally. But by “smart contracts” people usually mean contracts that can both be expressed computationally and execute automatically. Most often the idea is to set up a smart contract in a distributed computation environment like Ethereum, and then to have the code in the contract evaluate based on inputs from the computation environment.
Sometimes the input is intrinsic—like the passage of time (who could possibly tamper with the clock of the whole internet?), or physically generated random numbers. And in cases like this, one has fairly pure smart contracts, say for paying subscriptions, or for running distributed lotteries.
But more often there has to be some input from the outside—from something that happens in the world. Sometimes one just needs public information: the price of a stock, the temperature at a weather station, or a seismic event like a nuclear explosion. But somehow the smart contract needs access to an “oracle” that can give it this information. And conveniently enough, there is one good such oracle available in the world: Wolfram|Alpha. And indeed Wolfram|Alpha is becoming widely used as an oracle for smart contracts. (Yes, our general public terms of service say you currently just shouldn’t rely on Wolfram|Alpha for anything you consider critical—though hopefully soon those terms of service will get more sophisticated, and computational.)
But what about non-public information from the outside world? The current thinking for smart contracts tends to be that one has to get humans in the loop to verify the information: that in effect one has to have a jury (or a democracy) to decide whether something is true. But is that really the best one can do? I tend to suspect there’s another path, that’s like using machine learning to inject human-like judgment into things. Yes, one can use people, with all their inscrutable and hard-to-systematically-influence behavior. But what if one replaces those people in effect by AIs—or even a collection of today’s machine-learning systems?
One can think of a machine-learning system as being a bit like a cryptosystem. To attack it and spoof its input one has to do something like inverting how it works. Well, given a single machine-learning system there’s a certain effort needed to achieve this. But if one has a whole collection of sufficiently independent systems, the effort goes up. It won’t be good enough just to change a few parameters in the system. But if one just goes out into the computational universe and picks systems at random then I think one can expect to have the same kind of independence as by having different people. (To be fair, I don’t yet quite know how to apply the mining of the computational universe that I’ve done for programs like cellular automata to the case of systems like neural nets.)
There’s another point as well: if one has a sufficiently dense net of sensors in the world, then it becomes increasingly easy to be sure about what’s happened. If there’s just one motion sensor in a room, it might be easy to cover it. And maybe even if there are several sensors, it’s still possible to avoid them, Mission Impossible-style. But if there are enough sensors, then by synthesizing information from them one can inevitably build up an understanding of what actually happened. In effect, one has a model of how the world works, and with enough sensors one can validate that the model is correct.
It’s not surprising, but it always helps to have redundancy. More nodes to ensure the computation isn’t tampered with. More machine-learning algorithms to make sure they aren’t spoofed. More sensors to make sure they’re not fooled. But in the end, there has to be something that says what should happen—what the contract is. And the contract has to be expressed in some language in which there are definite concepts. So somehow from the various redundant systems one has in the world, one has to make a definite conclusion—one has to turn the world into something symbolic, on which the contract can operate.
So we basically have to put our faith and trust into machines that by doing computational expensive operations just for the sake of making them hard to break, will trade wasting a lot of energy for a little more trust.
The point is always "make it hard so it will be too expensive to crack it". but what if some country (or group of countries) really try to temper with the clock of the internet?
Are we sure the won't succed and make all of us use it?
If consensus is only established by powerful AIs, the ones with the most powerful AIs are creating the truth.
If there's one thing I really hate about all this machine-learning/AI scene it is this "Have a seemingly unsolvable problem? Don't worry, just let an AI that you don't understand and can't debug fix it for you!" silver-bullet mentality.
http://blog.stephenwolfram.com/2016/10/computational-law-sym...
And so it is with bitcoin, Ethereum, etc. The idea is that some particular thing that happened (“X paid Y such-and-such” or whatever) is shared and recorded in so many places that there can’t be any doubt about it. Yes, it’s in principle possible that all the few thousand places that actually participate in something like bitcoin today could collude to give a fake result. But the idea is that it’s like with gas molecules in a room: the probability is inconceivably small. (As it happens, my Principle of Computational Equivalence suggests that there’s more than an analogy with the gas molecules, and that actually the underlying principles at work are basically exactly the same. And, yes, there are lots of interesting technical details about the operation of distributed blockchain ledgers, distributed consensus protocols, etc., but I’m not going to get into them here.) It’s popular these days to talk about “smart contracts”. When I’ve been talking about “computational contracts” I mean contracts that can be expressed computationally. But by “smart contracts” people usually mean contracts that can both be expressed computationally and execute automatically. Most often the idea is to set up a smart contract in a distributed computation environment like Ethereum, and then to have the code in the contract evaluate based on inputs from the computation environment. Sometimes the input is intrinsic—like the passage of time (who could possibly tamper with the clock of the whole internet?), or physically generated random numbers. And in cases like this, one has fairly pure smart contracts, say for paying subscriptions, or for running distributed lotteries. But more often there has to be some input from the outside—from something that happens in the world. Sometimes one just needs public information: the price of a stock, the temperature at a weather station, or a seismic event like a nuclear explosion. But somehow the smart contract needs access to an “oracle” that can give it this information. And conveniently enough, there is one good such oracle available in the world: Wolfram|Alpha. And indeed Wolfram|Alpha is becoming widely used as an oracle for smart contracts. (Yes, our general public terms of service say you currently just shouldn’t rely on Wolfram|Alpha for anything you consider critical—though hopefully soon those terms of service will get more sophisticated, and computational.) But what about non-public information from the outside world? The current thinking for smart contracts tends to be that one has to get humans in the loop to verify the information: that in effect one has to have a jury (or a democracy) to decide whether something is true. But is that really the best one can do? I tend to suspect there’s another path, that’s like using machine learning to inject human-like judgment into things. Yes, one can use people, with all their inscrutable and hard-to-systematically-influence behavior. But what if one replaces those people in effect by AIs—or even a collection of today’s machine-learning systems? One can think of a machine-learning system as being a bit like a cryptosystem. To attack it and spoof its input one has to do something like inverting how it works. Well, given a single machine-learning system there’s a certain effort needed to achieve this. But if one has a whole collection of sufficiently independent systems, the effort goes up. It won’t be good enough just to change a few parameters in the system. But if one just goes out into the computational universe and picks systems at random then I think one can expect to have the same kind of independence as by having different people. (To be fair, I don’t yet quite know how to apply the mining of the computational universe that I’ve done for programs like cellular automata to the case of systems like neural nets.) There’s another point as well: if one has a sufficiently dense net of sensors in the world, then it becomes increasingly easy to be sure about what’s happened. If there’s just one motion sensor in a room, it might be easy to cover it. And maybe even if there are several sensors, it’s still possible to avoid them, Mission Impossible-style. But if there are enough sensors, then by synthesizing information from them one can inevitably build up an understanding of what actually happened. In effect, one has a model of how the world works, and with enough sensors one can validate that the model is correct. It’s not surprising, but it always helps to have redundancy. More nodes to ensure the computation isn’t tampered with. More machine-learning algorithms to make sure they aren’t spoofed. More sensors to make sure they’re not fooled. But in the end, there has to be something that says what should happen—what the contract is. And the contract has to be expressed in some language in which there are definite concepts. So somehow from the various redundant systems one has in the world, one has to make a definite conclusion—one has to turn the world into something symbolic, on which the contract can operate.