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Working in industry as a cryptography engineer.

To contact me, email paulgrub AT umail DOT iu DOT edu


Dec
6
revised Why should I use Authenticated Encryption instead of just encryption?
Fixed mis-statement of encryption security
Dec
6
comment Why should I use Authenticated Encryption instead of just encryption?
The only encryption scheme that ensures information-theoretic security is the one-time pad. IND-CPA encryption schemes only guarantee that the information cannot be extracted from the ciphertext by a probabilistic poly-time adversary.
Dec
5
comment Is an elliptic curve over $\mathbb{F}_p$ order preserving for the points $(x,y) \in \mathbb{Z}_p$?
Is that a justifiable assumption, though? Doesn't it depend greatly on the choice of $a$, $b$, and $p$?
Dec
5
comment Is an elliptic curve over $\mathbb{F}_p$ order preserving for the points $(x,y) \in \mathbb{Z}_p$?
I doubt they're order-preserving in the strict sense, because you'd eventually get reduced modulo $p$ if $y$ is too big. It might meet a related definition presented in Boldyreva's second paper on OPE where modular order preservation is the goal. I don't have it on hand but I'll try to dig up specifics and post them in another comment.
Dec
5
revised counting points on elliptic curve
Fixed equation formatting and field name
Dec
5
comment counting points on elliptic curve
As usual, Wikipedia is your friend here.
Dec
3
comment $\phi$ function in Dual_EC_DRBG
I think they're using 'bit vector' in a way that is specific to computations on elliptic curves.
Dec
3
comment $\phi$ function in Dual_EC_DRBG
Another resource on the backdoor: rump2007.cr.yp.to/15-shumow.pdf
Dec
1
comment Weak Stream Cipher cryptanalysis
No problem. Good luck with your assignment.
Dec
1
answered Weak Stream Cipher cryptanalysis
Dec
1
comment Weak Stream Cipher cryptanalysis
Hint: you can. Can you add or subtract terms of the subsequent expressions to get terms of the key sequence?
Dec
1
comment Weak Stream Cipher cryptanalysis
Forget RSA. For any unknown x, can you calculate $(x+c)^3$ for any integer $c$?
Nov
30
comment Can you help me understand hash-preserving encryption?
You're encrypting with the private key? What encryption scheme are you using?
Nov
30
accepted What is 'key agility' in relation to symmetric-key encryption?
Nov
29
revised Is this encryption scheme perfectly secure?
edited tags
Nov
29
comment Is this encryption scheme perfectly secure?
In the future, please tag homework questions as such.
Nov
27
comment becoming a cryptographer after math studies
Ahh ok. Most countries have intelligence agencies that hire mathematicians. If you can teach yourself some programming you can start looking at bigger tech companies like IBM, or if you do a PhD in applied math/crypto. In my mind the quicker of the two paths is learning more programming. Learn C and an object-oriented language like Java and you should be set.
Nov
27
comment becoming a cryptographer after math studies
With just a MS in math and no programming experience you'll be hard-pressed to find a job in the area. You don't need a ton of programming knowledge; it's more important to show domain-specific crypto knowledge. The NSA is always interested in hiring mathematicians to do crypto, and they'd probably train you in programming as well.
Nov
27
asked What is 'key agility' in relation to symmetric-key encryption?
Nov
26
comment Best group if one wants the discrete log problem to be hard?
Check NIST and ANSI standards for discrete log-based crypto, they discuss parameter generation.