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8h
comment RSA signature attack check on lowest 16 bytes - Implementation
@Seed3Key: look at what I wrote; not y = y.add(two) but y = y.add(two.pow(i-1))
8h
reviewed Leave Open How to reconstruct hash value to the original format?
9h
comment How does one launch a CPA2/CCA2?
I didn't realize that you were using packet captures. In any case, the next steps are: 1) enter the same password multiple times (to verify that the encoding method is determanistic), and 2) enter closely related passwords (e,g. 00000000 and 00000001) to see how minor changes modify the encoding. If the system is weak, that should lead you to what they're doing.
9h
comment RSA signature attack check on lowest 16 bytes - Implementation
That's wrong as well. If the $y^3$ and $hash$ agree in the lower $i$ bits, then you don't need to update $y$ at all (because you know that the lower $i$ bits are correct. If they don't agree, then you know you need to flip bit $i-1$ of $y$ (and since you initialize that bit to 0, that's the same as adding two,pow(i-1) to it.
11h
answered RSA signature attack check on lowest 16 bytes - Implementation
11h
revised Why do crypto libs use table lookups when they're vulnerable to timing attacks?
added 1123 characters in body
11h
answered Why do crypto libs use table lookups when they're vulnerable to timing attacks?
13h
reviewed Leave Open Enterprise message bus encryption
13h
reviewed Close An anonymous offline digital cash schema
13h
comment How does one launch a CPA2/CCA2?
Note: just because you could transport the registry, and log in doesn't mean that the system isn't hashing the password; what it might be doing during password entry is transmitting the hash in the registry. Instead, a better check would be to enter a short password and a very long one; is the registry for the short password shorter than that of the long one?
1d
comment Can non-assembly crypto libraries truly be secure against timing attacks?
You can't really control what's in the L1/L2 cache with assembly; that also depends on interrupts the CPU takes, and what the other cores are doing (neither of which are under the user's control). If you controlled the operating system as well, you would have hope; however I believe that's focusing in on the wrong question; the answer to timing attacks isn't having precisely consistent timing, but have any variation in the timing uncorrelated to any secret we have.
2d
reviewed No Action Needed Signature Verification: High level
2d
reviewed No Action Needed Understanding elliptic curve encryption
2d
revised Implementing CBC Encryption Using Decryption
edited tags
2d
answered Implementing CBC Encryption Using Decryption
Jul
31
comment Encryption algorithms larger than 256 Bit for “big data” encryption?
Are you asking "why do we generally restrict our (symmetric) keys to 256 bits"? If you aren't asking that, what are you asking?
Jul
31
answered How AES treat string input to encrypt data and what will happen if the cipher key is less than that expected?
Jul
31
comment One time pad ciphers in emails
The "keyword"??? If you're doing OTP, you don't distribute a keyword; instead, you distribute a random string of bits at least as long as the message you'll be sending...