@bobday said:
@Daid said:The encrypting with passphrase is possible, but I guess it would fail a bruteforce attempt.
Not if it's done properly. A nice 256-bit key Rijndael cipher would prevent any brute force attack.
However, this is still an impractical scheme. If every executable is unlocked by the same key, then that key (or the decrypted exe) will be made public the first time a copy of the program is unlocked.
If every executable has its own key, that will probably require asymmetric encryption and shipping a public key with the exe. The exe can then be modified to change the public key to a value with a known private key. This method can only work with software that runs online and must communicate with a central server. The server can maintain a list of approved public keys (sold copies of the program) and only issue the private key once to the program owner.
...at a cost of millions to the creator of the software in question, with very little return on investment. They'll still do it, though... gotta keep those thieving bastards from stealing our software!
*sigh*
You'd think people would know a little more about the product they sell than that.
But I guess it's hard to make someone understand something when his livelihood depends on him not understanding it.