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Jul
21
comment How to steganograph ownership information into members uploaded images?
Well, watermarking does not have to be obvious; in fact, we prefer it when it does not deteriorate the picture's main functionality, i.e. "being looked at". But, contrary to steganography, it is not a problem if the watermark is known to be there (in fact it is often the point: to deter copyists by making it known that there is a watermark).
Jul
21
comment How to steganograph ownership information into members uploaded images?
"watermarking is a lot harder to do than steganography". Yes, I think that I meant to say that, and also that I actually did.
Jul
21
answered Key derivation inside secure container of HSM
Jul
21
answered How to steganograph ownership information into members uploaded images?
Jul
21
answered How safe is password based key derivation in the case of long password?
Jul
21
answered Guid salt - string vs bytes[]
Jul
21
comment Is it complicated to deploy my own CA?
There is no such thing as a definitive, authoritative source for English typography (contrary to, say, French typography, because the French, in all their frenchness, created an Académie Française whose job is to be Right, always). Using a space before the question mark is relatively rare but not unheard of among English writers. It is often said to mimic French punctuation. The question mark itself is a relatively recent import into English (circa 1580, say some authors). Bottom-line: it is not absolutely incorrect to put a space; and I find it clearer that way.
Jul
20
answered Is it complicated to deploy my own CA?
Jul
19
comment do serial numbers for x509 certs need to be sequential or can they be timestamp's?
There is an official recommendation: for backward compatibility with some deployed implementations, the serial number encoded value should fit in 20 bytes -- thus you can use integers up to 2^159 (DER encoding of an INTEGER is signed, so there must be room for a sign bit).
Jul
17
comment Is it good practice to send passwords in separate emails, and why?
Most "best practices" are old lore turned into dogma through sedimentation, and parroted by people who like to think of themselves as "cybersecurity experts".
Jul
17
comment What Country, State and City should I choose when requesting an SSL certificate?
Theoretically, a PKCS#10 certificate request is supposed to be signed with the corresponding private key; this is called a "proof of possession" (i.e. you may request a certificate with a given public key only if you actually control the corresponding private key). What you would gain from buying a certificate with the public key of somebody else is unclear. Also, this self-signature cannot work for an encryption-only key (e.g. Diffie-Hellman). Many CA will verify the self-signature, mostly out of Tradition.
Jul
17
comment What Country, State and City should I choose when requesting an SSL certificate?
A PKCS#10 certificate request contains the public key you want to see appear in the certificate. It may contain a lot of other things (it is an extensible format, with extensions) but the CA is free to pick what it wants from the request and ignore the rest. The public key is about the only thing that the CA necessarily uses from the request, and most CA will use only that and ignore the rest.
Jul
17
comment What Country, State and City should I choose when requesting an SSL certificate?
There is no standardized method for the CA to put in the certificate the parts of the requests that it does not want to put in the certificate. If you take my meaning. Basically, if the CA decides to fully ignore the name you provided, then it fully ignores that name and you won't see it anywhere.
Jul
17
answered What Country, State and City should I choose when requesting an SSL certificate?
Jul
17
comment Guessing random bit with 100% accuracy
Yeah, I was so pleased with myself for thinking about this (I mean, even more pleased that I usually am) that I failed to notice that without this side-channel I actually had the correct answer.
Jul
17
revised Guessing random bit with 100% accuracy
added 351 characters in body
Jul
17
answered Guessing random bit with 100% accuracy
Jul
17
comment Guessing random bit with 100% accuracy
Probability of success is 75% is both programs answer randomly (since the prize is obtained when either or both guesses correctly).
Jul
17
awarded  Enlightened
Jul
17
awarded  Nice Answer