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Google’s fully homomorphic encryption compiler – a primer

jeremykun.com

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Re: Google’s fully homomorphic encryption compiler – a primer

#82
sounds like you could have anonymous currency.

heres our FHE bank. we both have accounts. the entire ledger is encrypted.

i give you 5 dollars, i have no idea what your starting and ending balance, but i am still able to initiate a transaction that will deduct 5 from mine, and add 5 to yours, and verify i actually have 5 to send, and the entire thing will be done without exchange of information about balances with any outside party. its just approved/declined by the algorithm. i can see my own balance with my own key, you can see your own balance with your own key, but we cant see each others balance. ---nor could anyone else including the bank---.

weird. and kind of scary. and most definitely illegal in the real world since the bank itself could never prove its reserve level of deposit met the percentage set by government.

Re: Google’s fully homomorphic encryption compiler – a primer

#83

Hmm, given that "mov is Turing-complete" [0], is it possible to get around the requirement that loops must be fully unrolled? Obviously you couldn't tell if your algorithm was finished, but if you could ask the key holder if the algorithm had completed or needed more work, you could theoretically compute any algorithm. What am I missing? [append] Perhaps, could you create a "fully homomorphically encrypted" 6502, whe…

The "mov is turing complete" thing is mostly about x86 mov having a lot of functionality. It can do arithmetic. The mov mnemonic basically encapsulates a bunch of functions (and opcodes), kind of like how git checkout can do at least ~3 distinct operations depending on arguments.

That said, to have unbounded loops, they either need:

- A branch at the end.

OR

- The use of pagefaults.

So even then, it's not quite just the mov instruction alone.

Re: Google’s fully homomorphic encryption compiler – a primer

#84

sounds like you could have anonymous currency. heres our FHE bank. we both have accounts. the entire ledger is encrypted. i give you 5 dollars, i have no idea what your starting and ending balance, but i am still able to initiate a transaction that will deduct 5 from mine, and add 5 to yours, and verify i actually have 5 to send, and the entire thing will be done without exchange of information about balances with an…

>> since the bank itself could never prove its reserve level of deposit met the percentage set by government

There’s no minimum reserve set by the fed anymore: https://www.federalreserve.gov/monetarypolicy/reservereq.htm

Re: Google’s fully homomorphic encryption compiler – a primer

#85

sounds like you could have anonymous currency. heres our FHE bank. we both have accounts. the entire ledger is encrypted. i give you 5 dollars, i have no idea what your starting and ending balance, but i am still able to initiate a transaction that will deduct 5 from mine, and add 5 to yours, and verify i actually have 5 to send, and the entire thing will be done without exchange of information about balances with an…

I love/hate this. It's one of those ideas that's incredibly appealing to people who already have other ways of doing it, and incomprehensible to people who would actually benefit from it. Most things of that ilk get blown up because once it's peddled to the masses, consumers don't verify that it's actually run the way it's supposed to be run, and someone writes in a backdoor (FTX). Then it just takes a few hyped up claims and burst bubbles before it becomes a punchline.

What would be sort of awesome, though, would be a distributed bank (or prediction market, or casino) along these lines. If every node can donate processing power to run totally encrypted transactions, it's a game changer. You could finally rely on client-side processing to deal poker hands and process game states without a central server, for example.

Re: Google’s fully homomorphic encryption compiler – a primer

#86

sounds like you could have anonymous currency. heres our FHE bank. we both have accounts. the entire ledger is encrypted. i give you 5 dollars, i have no idea what your starting and ending balance, but i am still able to initiate a transaction that will deduct 5 from mine, and add 5 to yours, and verify i actually have 5 to send, and the entire thing will be done without exchange of information about balances with an…

>> since the bank itself could never prove its reserve level of deposit met the percentage set by government There’s no minimum reserve set by the fed anymore: https://www.federalreserve.gov/monetarypolicy/reservereq.htm

Other countries exist.

Re: Google’s fully homomorphic encryption compiler – a primer

#87
When I first learned about homomorphic encryption it gave me the idea of "cryptographic AI", as some sort of sci-fi writing prompt. Suppose compute is readily available to interstellar civilizations but actually designing a (super)intelligent AI is difficult. Then it could be economically feasible for cryptographic AI to exist. These are descriptions of AIs that run under homomorphic encryption, where the private key is only known by the AI itself. The description of the AI program and its state is spread throughout many locations and generally runs in a decentralized way. Planet earth might receive a segment of a cryptographic AI and make deal: Earth executes the program with some inputs it may choose to compute a solution to a problem. The program can be given inputs via a public key. The execution of the program can not be modified or manipulated since it is running under homomorphic encryption. What the AI gets in return is that earth provides it with additional compute that it may use for its own purposes. Earth furthermore allows the AI to transmit updated fragments of state into the stars. Over the course of many years, the pieces of state of the decentralized AI spread throughout the galaxy combine to represent the thoughts and actions of a singular entity. If earth modified the computations then the transmitted state could cryptographically be seen to not be valid, and hence would not be used in the decentralized galaxy spanning computation of the AI. Furthermore if earth cheats the AI in the deal then there may be consequences such as relativistic kinetic kill projectiles.

Re: Google’s fully homomorphic encryption compiler – a primer

#88
This is all interesting and I’m thinking now with all the talk of privacy and data sovereignty etc why this is coming out or Google now and not Apple? Anyone know if Apple is thinking along these lines? Would be nice if we could get performant computation on things without having to decrypt our own data. Then again my understanding and real world applications of homomorphic encryption is pedestrian at best.

What I do really enjoy is the author’s tone and style. The article was fun to read and easy to follow and it seems like a really cool project.

Re: Google’s fully homomorphic encryption compiler – a primer

#89

sounds like you could have anonymous currency. heres our FHE bank. we both have accounts. the entire ledger is encrypted. i give you 5 dollars, i have no idea what your starting and ending balance, but i am still able to initiate a transaction that will deduct 5 from mine, and add 5 to yours, and verify i actually have 5 to send, and the entire thing will be done without exchange of information about balances with an…

Sure. And then, after you've transferred 5 dollars to me, I say "What 5 dollars? What are you talking about?" and refuse to hand over the thing that you thought you bought.

Add perfect anonymity to the mix and I get to do it over and over again, too.

Re: Google’s fully homomorphic encryption compiler – a primer

#90

sounds like you could have anonymous currency. heres our FHE bank. we both have accounts. the entire ledger is encrypted. i give you 5 dollars, i have no idea what your starting and ending balance, but i am still able to initiate a transaction that will deduct 5 from mine, and add 5 to yours, and verify i actually have 5 to send, and the entire thing will be done without exchange of information about balances with an…

You don't need FHE for that. It's possible through some zero-knowledge schemes, such as zk-SNARKS, which is implemented in and popularized by shielded transactions on Zcash.
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