Sea Skimmer wrote:If a one time pad is truly random and the pad is kept completely secure and never reused then its unbreakable; but many one time pads are not in fact truly random and some kind of cipher or seed is used to create them that a computer might work out.
Right - if someone using a psuedorandom number generator and figures out the generator, the seed and when it has been sampled, you can break the pad. There are true RNGs (for example, sampling radioactive sources) but those are unwieldy.
MKSheppard wrote:Ironically enough, I got the idea while thinking of how "no cd" cracks are made.
Basically, no CD cracks work on the basis of the machine code in your executable. The cracker finds the hexadecimal interrupt in the EXE file which is the "IF FAIL THIS, GOTO END PROGRAM" and modifies the hexadecimal to bypass it.
Well to improve the analogy - more like a game trainer, which invades the program's process space and rewrites commands without modifying the original file (a no-CD crack traditionally modifies the executable file).
EDIT: Actually, the best thing I can think of - awhile back there was a flaw in the way Windows parsed a certain type of image format (WMF). Just by displaying the image a system could be compromised. /END-EDIT
This is an interesting artifact of most computer architectures where "data" and "program" are not distinguished from each other - the Von Neumann architecture. That said, in recent years, even low-end commercial systems are able to recognize that some regions of memory are purely data and will not be executed, defending against such an attack.
I'm sure that simply entering a random number for the offset will cause bad things to happen, like the system locking, or shutting down.
You'd also have to know where to point to as well, etc. However, given that many military systems are probably not field-upgradeable once you have a copy and you know what you're doing, you can wreak havoc.