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Oct
3
comment Is 512-bit RSA still safe for signature generation?
All Windows 2000, XP and more that I have come across always had several CSP installed, including the "strong" ones. Remember that IE uses them for SSL; if a basic Windows could not do more than 512-bit RSA, IE would not be able to handle common HTTPS sites.
Oct
2
comment Is 512-bit RSA still safe for signature generation?
I seriously doubt that WinXP cannot go beyond 512 bits, especially since I have done a lot of RSA-1024 with the CSP which come with a stock Windows 2000. The "base CSP" was limited to 512 bits because of the export regulations of that time, but they were lifted near the end of the Clinton presidency.
Oct
2
answered Calculating cycles per byte
Oct
2
comment Could the Enigma algorithm be classified as a Feistel network?
Twofish is a Feistel variant (it has a few extra elements such as word rotations, but the basic Feistel structure is there). MD5 is not even a symmetric cipher; however, it is possible to say that the core of the "compression function" in MD5 is akin to a generalized Feistel structure, albeit with the message and key swapping their roles. This kind of stretches the limits of the terminology.
Oct
2
answered Could the Enigma algorithm be classified as a Feistel network?
Sep
27
comment Must the order of the groups in a bilinear map be the same?
@curious: there are two traditional ways to denote a group operation: as a multiplication (with "1" as neutral), or as an addition (with a "0"). To understand the analogy "pairing is like a multiplication", you have to denote all your groups with additions, so no "1", only "0". For a lot of historical reasons, pairings where first described with multiplications everywhere; then, for elliptic curves, we talk about "additions", but, still traditionally, we use multiplication for pairing results.
Sep
27
comment Must the order of the groups in a bilinear map be the same?
@curious: sorry, that's the usual confusion. In the first part of the post, I use multiplicative notation on the groups; in the second part, I use additive. With the additive notation for groups $G_1$, $G_2$ and $G_n$, that's $e(rg_1, g_2) = 0$ because $rg_1 = 0$ and $e(0,x) = 0$ by bilinearity.
Sep
27
comment Must the order of the groups in a bilinear map be the same?
@curious: because $g_1^r = 1$ (group $G_1$ has order $r$) and bilinearity implies that $e(1,x) = 1$ for all $x$.
Sep
21
awarded  Custodian
Sep
21
awarded  Nice Answer
Sep
20
answered Is RSASSA-PKCS1-v1_5 a good signature scheme for new systems?
Sep
11
comment Which is more secure, using just bcrypt or SRP?
@133794m3r: if you want to combine SRP with bcrypt, use bcrypt on the password on both client and server, and use the output of bcrypt as the "password" that SRP wishes to use.
Sep
10
answered Which is more secure, using just bcrypt or SRP?
Sep
9
answered Is it safe to use file's hash as IV?
Sep
7
answered Signature and Timestamp for Long Term Document Archival Question
Aug
31
comment Can you help me with this Random Number Generator function?
@maaartinus: I tend to think so, but it would deserve some careful analysis.
Aug
30
answered Can you help me with this Random Number Generator function?
Aug
24
awarded  Constable
Aug
24
answered What is the effect of the different AES key lengths?
Aug
16
awarded  Good Answer