4 ms·

If we had proper homorphic encryption, we could use regular home user machines for a cloud, airbnb style. You can't do that today because the security risks are

by tfha 8y ago

If we had proper homorphic encryption, we could use regular home user machines for a cloud, airbnb style. You can't do that today because the security risks are completely unmanageable. But that all changes with homomorphic encryption. Today it's not practical, but we see advances like this every year, maybe in a decade it will be practical.

betterunix2 8y ago
You need more than FHE for that; just because I cannot see what I am computing does not mean I will compute the answer correctly. There are ways this can be resolved but it pushes practicality even further back.
- dlubarov 8y ago
  Not sure what you mean? Correct evaluation (modulo some negligible error) is part of the usual FHE definition.
  - JadeNB 8y ago
    Perhaps it’s referring to human malice rather than mathematical error: that we’d want some sort of certification that the operation performed off-site was actually the one requested?
  - tylersmith 8y ago
    You can't evaluate the correctness/trust the result without performing the computation yourself or receiving a proof of correctness, e.g. a SNARK.
- chaboud 8y ago
  Is it not practical to just saddle the dataset and compute request with a canary payload that is easily computable by the requestor? If one can spoof the canary payload effectively, one would have broken the FHE scheme, probabilistically, right? Unless I'm thinking about this wrong, the FH part of FHE makes this a pretty solvable problem. Is this not already fundamental to any FHE scheme?
  - betterunix2 8y ago
    Maybe in some cases that is possible, but it is also possible that your function requires as much time to verify as the FHE evaluator would spend on (honestly) computing the result. In other words it would make outsourcing pointless; this is briefly discussed in the related work section of this paper: https://eprint.iacr.org/2014/202.pdf https://eprint.iacr.org/2014/202.pdf You also have to be careful to ensure that the canary cannot be identified in the plaintext; otherwise the evaluator can homomorphically identify the canary (i.e. it can compute the canary values honestly and cheat everywhere else).

by tfha 8y ago

betterunix2 8y ago

You need more than FHE for that; just because I cannot see what I am computing does not mean I will compute the answer correctly. There are ways this can be resolved but it pushes practicality even further back.

dlubarov 8y ago
Not sure what you mean? Correct evaluation (modulo some negligible error) is part of the usual FHE definition.
- JadeNB 8y ago
  Perhaps it’s referring to human malice rather than mathematical error: that we’d want some sort of certification that the operation performed off-site was actually the one requested?
- tylersmith 8y ago
  You can't evaluate the correctness/trust the result without performing the computation yourself or receiving a proof of correctness, e.g. a SNARK.
chaboud 8y ago
Is it not practical to just saddle the dataset and compute request with a canary payload that is easily computable by the requestor? If one can spoof the canary payload effectively, one would have broken the FHE scheme, probabilistically, right? Unless I'm thinking about this wrong, the FH part of FHE makes this a pretty solvable problem. Is this not already fundamental to any FHE scheme?
- betterunix2 8y ago
  Maybe in some cases that is possible, but it is also possible that your function requires as much time to verify as the FHE evaluator would spend on (honestly) computing the result. In other words it would make outsourcing pointless; this is briefly discussed in the related work section of this paper: https://eprint.iacr.org/2014/202.pdf https://eprint.iacr.org/2014/202.pdf You also have to be careful to ensure that the canary cannot be identified in the plaintext; otherwise the evaluator can homomorphically identify the canary (i.e. it can compute the canary values honestly and cheat everywhere else).