# Tag Info

## Hot answers tagged java

6

An attack would be trivial if the seed of the RNG was only 32 bits; just enumerate the seeds, and test which matches the intercepted messages. That's easy. However the default Java Random class uses a 48-bit state and seed (which would still be attackable, though $2^{16}$ times less easily), and there are safe subclasses, thus use of Random does not imply ...

4

No, this is not a safe implementation; from the modulus and the public exponent, it would be possible to factor the modulus. The reason is that you pick the private exponent to be small; one-fifth the size as the modulus. It's known that knowledge of a public exponent corresponding to that is sufficient to factor. The obvious question is "why are you ...

2

To begin with, let's assume that the attacker cannot extract the AES key from your software. That means the best they can do is a chosen-plaintext attack on AES: choose a block $Y$, request its encryption $Z$, repeat as many times as desired and try to use the results to figure out something useful about the encryption of other plaintext blocks. Since AES ...

1

embedding a symmetrical (AES) key in your software really is pointless - an attacker could easily extract the key and generate their own software license key, or worse, create a small program (a crack) that allows other users to generate their own license keys I recommend RSA - generate 'Z' (as per your question) by signing the data 'Y' with a private key, ...

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