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A whole new encryption scheme that will change my world. I’ll share it here when it’s polished up. It allows you to encrypt anything and can be decrypted by an

A whole new encryption scheme that will change my world. I’ll share it here when it’s polished up. It allows you to encrypt anything and can be decrypted by anyone after a certain point in the future has passed. It uses the new NMA announcements (signed timestamps) from the Galileo GPS satellites to “prove” the time has passed and generate the decryption key.

beecafe 4y ago
How does it work? I can imagine a program that checks if it sees a correctly signed message of the right time, but that program would then have to decrypt the payload, and I don't know how the key for the payload could be derived from the as yet nonexistent timestamp.
- withinboredom 4y ago
  It’s basically a SNARK (cryptographic program) where the verification program itself is part of the cypher text and instead of outputting 0 or 1, you get decryption.
RealityVoid 4y ago
Not sure of the use cases, but it sounds very cool!
- withinboredom 4y ago
  Basically a digital time locked safe. You could send something to a reporter and not even the NSA could open it until the appropriate time. You could encrypt crypto-wallet keys with it and your heir can’t open them until after turning a certain age. My use case: my wife or myself write a letter that can’t be opened until some point in the future. Every year, we delete the old letter and write a new one. This is “in case we die” so it’s addressed to loved ones. Right now, we can theoretically read each other’s letters if we wanted to, but this encryption doesn’t require us trusting each other, the service we host them on, or anything.
  - rozab 4y ago
    Well, I'm sure the NSA would have the Galileo private keys? Seems eminently useful
    - withinboredom 4y ago
      If that were true, potentially every intelligence agency on earth would have a copy and it would defeat the purpose of it since anyone could spoof gps signals. It seems entirely within Europe’s interest to keep it out of any other agency’s hands as it would defeat the purpose of it.
      - thfuran 4y ago
        These sorts of agencies have a habit of getting their hands on things that other people didn't intend them to.
        withinboredom 4y ago
        Well, hopefully they get into a habit of routinely rotating the key.
        RealityVoid 4y ago
        Would that not break your system though? I admit my lack of knowledge in public key infrastructure.
        withinboredom 4y ago
        I just checked and it looks like[1] this happens at least once a year, specifically to guard against this kind of attack. It doesn’t break the chain of hashes though. 1: https://www.euspa.europa.eu/sites/default/files/calls_for_proposals/annex_1-rd4.pdf https://www.euspa.europa.eu/sites/default/files/calls_for_pr...
  - RealityVoid 4y ago
raihansaputra 4y ago
Oooh i've always thought about this but never dug deeper into where can one get a signed proof of time. Would really like to see how this will go! I can see a lot of things built on it ("validated" Web Archive, press/betting market, etc). Maybe the GPS timestamps will become the world standard, maybe it will not be. I assume the NMA announcements have a public key to verify/decrypt the message.
- withinboredom 4y ago
  Yeah, the protocol looks really robust. It should also allow some protection against spoofing signals. https://gssc.esa.int/navipedia/index.php/Galileo_Open_Service_Navigation_Message_Authentication https://gssc.esa.int/navipedia/index.php/Galileo_Open_Servic...
garaetjjte 4y ago
Nice idea, but.. that's not possible.
- withinboredom 4y ago
  Why do you think that? I’ve already successfully encrypted and decrypted messages, so I’m very well aware of how possible it is.
  - remram 4y ago
    I am also skeptical, though I am no expert. SNARK are zero-knowledge proofs, they are intended to give a proof that a result was computed correctly, not prevent an unwanted computation altogether. The fact that you can decrypt after the time passed is of course the easy part, preventing decryption before then is the problem.
    - withinboredom 4y ago
      Yeah, there’s no telling how secure it is. Works, yes. Easily circumventable, maybe, maybe not. There’s a lot of math involved and I’m by no means an expert at any of it or guaranteed to have implemented everything correctly. For my personal purposes it’s 100% secure unless you know wtf you are looking at (much like a one-time-pad). Once the code and algorithms are published, it’s only secure until someone breaks it.
neapolisbeach 4y ago
I built a similar scheme for a class project, but relying on verifiable delay functions [1] to provide the time lock. Might be something you’re interested in. [1] https://eprint.iacr.org/2018/601.pdf https://eprint.iacr.org/2018/601.pdf
- withinboredom 4y ago
  Indeed! It looks familiar until you get to the verification (very SNARKy).

beecafe 4y ago

How does it work? I can imagine a program that checks if it sees a correctly signed message of the right time, but that program would then have to decrypt the payload, and I don't know how the key for the payload could be derived from the as yet nonexistent timestamp.

withinboredom 4y ago
It’s basically a SNARK (cryptographic program) where the verification program itself is part of the cypher text and instead of outputting 0 or 1, you get decryption.

RealityVoid 4y ago

Not sure of the use cases, but it sounds very cool!

withinboredom 4y ago
Basically a digital time locked safe. You could send something to a reporter and not even the NSA could open it until the appropriate time. You could encrypt crypto-wallet keys with it and your heir can’t open them until after turning a certain age. My use case: my wife or myself write a letter that can’t be opened until some point in the future. Every year, we delete the old letter and write a new one. This is “in case we die” so it’s addressed to loved ones. Right now, we can theoretically read each other’s letters if we wanted to, but this encryption doesn’t require us trusting each other, the service we host them on, or anything.
- rozab 4y ago
  Well, I'm sure the NSA would have the Galileo private keys? Seems eminently useful
  - withinboredom 4y ago
    If that were true, potentially every intelligence agency on earth would have a copy and it would defeat the purpose of it since anyone could spoof gps signals. It seems entirely within Europe’s interest to keep it out of any other agency’s hands as it would defeat the purpose of it.
    - thfuran 4y ago
      These sorts of agencies have a habit of getting their hands on things that other people didn't intend them to.
      - withinboredom 4y ago
        Well, hopefully they get into a habit of routinely rotating the key.
        RealityVoid 4y ago
        Would that not break your system though? I admit my lack of knowledge in public key infrastructure.
        withinboredom 4y ago
        I just checked and it looks like[1] this happens at least once a year, specifically to guard against this kind of attack. It doesn’t break the chain of hashes though. 1: https://www.euspa.europa.eu/sites/default/files/calls_for_proposals/annex_1-rd4.pdf https://www.euspa.europa.eu/sites/default/files/calls_for_pr...
- RealityVoid 4y ago

raihansaputra 4y ago

Oooh i've always thought about this but never dug deeper into where can one get a signed proof of time. Would really like to see how this will go! I can see a lot of things built on it ("validated" Web Archive, press/betting market, etc). Maybe the GPS timestamps will become the world standard, maybe it will not be. I assume the NMA announcements have a public key to verify/decrypt the message.

withinboredom 4y ago
Yeah, the protocol looks really robust. It should also allow some protection against spoofing signals. https://gssc.esa.int/navipedia/index.php/Galileo_Open_Service_Navigation_Message_Authentication https://gssc.esa.int/navipedia/index.php/Galileo_Open_Servic...

garaetjjte 4y ago

Nice idea, but.. that's not possible.

withinboredom 4y ago
Why do you think that? I’ve already successfully encrypted and decrypted messages, so I’m very well aware of how possible it is.
- remram 4y ago
  I am also skeptical, though I am no expert. SNARK are zero-knowledge proofs, they are intended to give a proof that a result was computed correctly, not prevent an unwanted computation altogether. The fact that you can decrypt after the time passed is of course the easy part, preventing decryption before then is the problem.
  - withinboredom 4y ago
    Yeah, there’s no telling how secure it is. Works, yes. Easily circumventable, maybe, maybe not. There’s a lot of math involved and I’m by no means an expert at any of it or guaranteed to have implemented everything correctly. For my personal purposes it’s 100% secure unless you know wtf you are looking at (much like a one-time-pad). Once the code and algorithms are published, it’s only secure until someone breaks it.

neapolisbeach 4y ago

I built a similar scheme for a class project, but relying on verifiable delay functions [1] to provide the time lock. Might be something you’re interested in. [1] https://eprint.iacr.org/2018/601.pdf https://eprint.iacr.org/2018/601.pdf

withinboredom 4y ago
Indeed! It looks familiar until you get to the verification (very SNARKy).