Here’s a blog post from a former employee at a new startup comparing kdb against some alternative databases for common operations on financial data: https://medium.com/prooftrading/selecting-a-database-for-an-...
49 karma · joined April 22, 2013
https://www.cs.columbia.edu/~luke/
Here’s a blog post from a former employee at a new startup comparing kdb against some alternative databases for common operations on financial data: https://medium.com/prooftrading/selecting-a-database-for-an-...
I don't think that doing this stifles innovation (In fact, I think requiring crypto innovations to have security justifications is probably better overall for innovation in the field)
From the Wikipedia page for "Neural cryptography", it seems like there's some success in using NN's for cryptanalysis, but not for constructions...
Edit: Do you mean the Google GAN experiment? (https://arxiv.org/pdf/1610.06918v1.pdf) Ahh ok, well at least for this there looks like an attempt at defining a security model (security against some other NN). I don't really believe the security model is realistic (how do we know NN's are really that effective as adversaries?), but at least there is a model, so calling that "encryption" sits somewhat better with me. I'm pretty sure this is not what's being used by Numerai since it seems like it would not result in ciphertexts with the structure necessary to perform ML operations on.
Edit2: Maybe you're right and it is more advanced. In any case, as a crypto nerd I wish they would disclose what they are actually doing / the rationale instead of tantalizingly suggesting that they have made (what would be) a breakthrough in a practical use case of advanced encryption schemes, but not saying how.
I still don't think it's fair to market their method as comparable to Aslett's scheme or "standard" notions of homormorphic/order preserving encryption, no matter how "chill" they are :)
Their (closed-source) method of obfuscating their data apparently does have the property that it preserves the structure of the data, but calling it "structure-preserving encryption" is misleading imo since it risks confusing it with standard notions of encryption and structure-preserving encryption which have much stronger security guarantees.
(Their marketing seems to encourage this conflation by, for example, citing academic advances in standard notions of homomorphic encryption and SPE and implying that these advances have enabled Numerai's technology)
https://medium.com/numerai/encrypted-data-for-efficient-mark...
Universities make much more money off their Masters students, most of whom are international, and pay full tuition (or someone does for them).
Given this "encrypted" X , y dataset, I could easily find the unencrypted version... (even if I don't know 20 or -0.5, this still reveals so much of the structure that I don't believe it provides any real protection against anything except the most lazy attackers)
I am pretty sure homomorphic encryption is not being used. I think if they are doing anything rigorous, maybe they are using order-preserving encryption (http://www.cc.gatech.edu/~aboldyre/papers/bclo.pdf). This would mean that the only valid operations on the ciphertexts are comparison operations. I can't seem to find anywhere where numer.ai actually says how to interact with the "encrypted" data. I think it's a little strange that they would suggest that they are using homomorphic encryption yet have only comparison operations actually make sense on their "encrypted" data.
A second hypothesis would be that no encryption is being used at all, and this is just unlabeled features that have been renormalized within [0,1].
A third would be that order-preserving encryption is being used, but in an ineffective way which is basically just resulting in the second scenario. (understanding the security guarantees of order-preserving encryption is practice is very complicated)
Isn't it the case that if I just removed the labels, and renormalized all my data to fall in [0, 1], then what I end up with looks a lot like what Numer.ai gives you?
I'm not aware of any homomorphic encryption / structure preserving schemes that have homomorphic evaluation on ciphertexts equivalent to literal multiplication and addition of ciphertexts, and this seems to be what they want you to do to train your model. (unless I'm misunderstanding how to interact with the "encrypted" dataset)
EDIT: seems like most people think they are using Order Preserving Encryption, which allows one to compare ciphertexts with the "less than" predicate. This makes more sense looking at what they give, but I never saw anything where they say "only do comparisons on the encrypted data."
Keybase doesn't have my private key (only I do), so they can't re-encrypt the contents.
(sorry if I misunderstood your question)
http://www.coindesk.com/cryptowall-325-million-bitcoin-ranso...
For (2), could you also find a way to get the FBI to release a statement saying you are trustworthy?
The hacker wants to be trustworthy here so that new victims will be more likely to pay the ransom because they believe they will actually get their data back.