4 ms·

If you want someone to understand security, just send him to a university mathematics department for four years. This is a testable assertion. I've met a bunc

If you want someone to understand security, just send him to a university mathematics department for four years. This is a testable assertion. I've met a bunch of people in data security in the last few years. In fact, I do know one with a math degree and he's very sharp. But I still think the premise is ridiculous. Math proofs are tall towers of lemmas and theorems existing in an insulated universe. Logical and rational thought are critical, yes, but in real world security you must be very careful not to build your towers that high. Instead you need a defense-in-depth strategy, one which assumes at least some of your assumptions are going to be violated on a regular basis. Seen in a crypto paper: * An attack on [cryptographic primitive] A implies an attack on [cryptographic primitive] B. * B is not the subject of this paper. * Therefore, A is proven secure.

ihodes 15y ago
Your premise is interesting, your example (and supposed proof?) is a strawman. I don't think Colin is saying the best security people are mathematicians. Rather, he's saying the best mathematicians are well-suited to be security professionals.
kragen 15y ago
Unfortunately, your A-B example is about the best we can do for cryptographic proofs at this point. We don't even know how to prove P≠NP at this point, and worse, as far as I know, we don't even know how to design cryptosystems whose attacks would reduce to a known NP-complete problem. The best we know how to do so far is math problems that nobody has found an efficient algorithm for yet, such as discrete logarithms and integer factorization.
- marshray 15y ago
  Which is all fine, and it's all very valuable work of course. The problem is when cryptographers say something is "proven secure" it turns out not to mean that nobody can hack it, especially in an actual deployed system. This is surprising to many people.
bane 15y ago
It's a good point. My uni's Master's level security coursework was surprisingly very math heavy. A typical class started with about 60 people and ended with about 10 very exhausted students. Folks without a strong math background, expecting to learn how to tweak file permissions or domain controllers or something were in for a rude surprise when we cracked open a textbook that consisted of mostly greek letters and pages of proofs and lemmas. But having studied some hard maths in my undergrad, I walked away with a feeling I couldn't shake that much of it was form over function. We spent weeks showing proofs of very simple security circumstances "atomic changes to an access control list are provable secure" and then summed it up with "anything more complex than this, like nonatomic changes to an ACL are provably insecure". And that was that. I came away very disappointed in the field as a whole, that instead of spending time pragmatically finding ways of improving security in an applied sense, we were spending an inordinate amount of time cranking through higher level maths that just showed the whole thing was hopeless in the end anyways. Depressing.
- omaranto 15y ago
  It may be disappointing that many things are provably insecure, but if they are, isn't it good to know that?
  - bane 15y ago
    Absolutely. It's totally not an area I plan on working in, but it was a fascinating insight into the field. I ended up respecting it quite a bit more, there was a lot more thought in the field than I had expected.
- marshray 15y ago
  But now you have really good ammunition when you need to explain to someone else why his race-condition laden system of nonatomic asynchronous updates is insecure.

ihodes 15y ago

Your premise is interesting, your example (and supposed proof?) is a strawman. I don't think Colin is saying the best security people are mathematicians. Rather, he's saying the best mathematicians are well-suited to be security professionals.

kragen 15y ago

Unfortunately, your A-B example is about the best we can do for cryptographic proofs at this point. We don't even know how to prove P≠NP at this point, and worse, as far as I know, we don't even know how to design cryptosystems whose attacks would reduce to a known NP-complete problem. The best we know how to do so far is math problems that nobody has found an efficient algorithm for yet, such as discrete logarithms and integer factorization.

marshray 15y ago
Which is all fine, and it's all very valuable work of course. The problem is when cryptographers say something is "proven secure" it turns out not to mean that nobody can hack it, especially in an actual deployed system. This is surprising to many people.

bane 15y ago

It's a good point. My uni's Master's level security coursework was surprisingly very math heavy. A typical class started with about 60 people and ended with about 10 very exhausted students. Folks without a strong math background, expecting to learn how to tweak file permissions or domain controllers or something were in for a rude surprise when we cracked open a textbook that consisted of mostly greek letters and pages of proofs and lemmas. But having studied some hard maths in my undergrad, I walked away with a feeling I couldn't shake that much of it was form over function. We spent weeks showing proofs of very simple security circumstances "atomic changes to an access control list are provable secure" and then summed it up with "anything more complex than this, like nonatomic changes to an ACL are provably insecure". And that was that. I came away very disappointed in the field as a whole, that instead of spending time pragmatically finding ways of improving security in an applied sense, we were spending an inordinate amount of time cranking through higher level maths that just showed the whole thing was hopeless in the end anyways. Depressing.

omaranto 15y ago
It may be disappointing that many things are provably insecure, but if they are, isn't it good to know that?
- bane 15y ago
  Absolutely. It's totally not an area I plan on working in, but it was a fascinating insight into the field. I ended up respecting it quite a bit more, there was a lot more thought in the field than I had expected.
marshray 15y ago
But now you have really good ammunition when you need to explain to someone else why his race-condition laden system of nonatomic asynchronous updates is insecure.