CptPatriot Posted July 29, 2017 Report Share Posted July 29, 2017 I know that the power Mind Link is often used as an encrypted radio, but if you have the means to try to decrypt the radio link, how would you adjudicate it so you can read the transmissions? Quote Link to comment Share on other sites More sharing options...
mrinku Posted July 29, 2017 Report Share Posted July 29, 2017 Most likely through opposed KS:Cryptography and Computer Programming rolls. How realistic you want to get would depend on setting and who's trying to break whom, which would also affect the time frame. Mechanon intercepting a PVP message is probably going to break it in a few seconds. A lone agent with a laptop might need more time than is available. Captain Future with his 35th Century Universal Translator might not even realise it's encrypted. Quote Link to comment Share on other sites More sharing options...
CptPatriot Posted July 29, 2017 Author Report Share Posted July 29, 2017 Well, it was meant as a general question, however we're dealing with a Champions game where an AI from 2021 trying to break a "quantum computer" from 1980's communications link. I think in this case, it would be more fair to compare the relative power of the computers as they were bought than special effects. Quote Link to comment Share on other sites More sharing options...
massey Posted July 29, 2017 Report Share Posted July 29, 2017 The whole purpose of buying it as Mind Link is to prevent that sort of thing. Quote Link to comment Share on other sites More sharing options...
mrinku Posted July 29, 2017 Report Share Posted July 29, 2017 Well... special effects are important. If it's been defined as using radio, intercepting the signals by radio isn't much of a problem. It's down to the decryption of those signals. Of course a Quantum computer may not be using radio at all. QBit manipulation uses "spooky action at a distance". But for a normal 4 colour campaign, opposed Computer Programming rolls works for me, especially if the 1980's computer is not an AI. Quote Link to comment Share on other sites More sharing options...
IndianaJoe3 Posted July 30, 2017 Report Share Posted July 30, 2017 I know that the power Mind Link is often used as an encrypted radio, but if you have the means to try to decrypt the radio link, how would you adjudicate it so you can read the transmissions? IMHO, resolving this is going to be a bit more complicated than previous posters suggest. The whole point of buying encrypted radio as a Mind Link is that it can't be decrypted trivially. I'd probably use something like this: Radio De-Scrambler: Telepathy 8d6, Alternate Combat Value (uses OCV against DCV; +0), Attack Versus Alternate Defense (Power Defense; +0) (40 Active Points); Limited Power Power loses about half of its effectiveness (Encrypted radio communications only; -1), Requires A Roll (Cryptography roll; Must be made each Phase/use; -1), Affected as Radio Sense Group (-1/4) Cost: 12 pts Mechanically, the descrambler reads the mind of the person in the Mind Link. I'm not 100% happy with this build - the Cryptography skill roll should be contested and there's really no, "defense" as such because the descrambler is passively listening to a broadcast. Still, it lets the encrypted radio link be monitored without invoking GM fiat. Quote Link to comment Share on other sites More sharing options...
mrinku Posted July 30, 2017 Report Share Posted July 30, 2017 IMHO, resolving this is going to be a bit more complicated than previous posters suggest. The whole point of buying encrypted radio as a Mind Link is that it can't be decrypted trivially. I agree, but if the circumstances are non-trivial a GM may allow it. An enemy might capture a person with a secured communicator, intrude into the computer system itself, or have supertech advantage as discussed earlier. It's a sobering thought that a time-traveller could likely crack Enigma using a smartphone app... Quote Link to comment Share on other sites More sharing options...
IndianaJoe3 Posted July 30, 2017 Report Share Posted July 30, 2017 I agree, but if the circumstances are non-trivial a GM may allow it. An enemy might capture a person with a secured communicator, intrude into the computer system itself, or have supertech advantage as discussed earlier. It's a sobering thought that a time-traveller could likely crack Enigma using a smartphone app... I think that defining, "non-trivial" is where our disagreement is. I don't think that simply, "having supertech" is sufficient justification to nullify a power that a character has paid points for. Yes, my $20 smartphone could easily decrypt Enigma communications, but only if I had the right app on it. If I don't have (pay points for) the app, I'm SOL. Of course, if decrypting radio transmissions is expected in your game, maybe a straight Mind Link isn't the right build. Quote Link to comment Share on other sites More sharing options...
Crusher Bob Posted July 31, 2017 Report Share Posted July 31, 2017 In addition, 'good' encyrption falls somewhere between 'can't be decrypted at all without the key' (properly implemented one time pads) to merely 'if you used all the matter in the universe to make a computer and tried to brute force this problem, it would still take longer than the expected lifespan of the universe'. Alas, IRL encryption is broken because someone did something stupid, and for a game, having your good roll on decryption produce the result of 'this guy used his birthday and pet's name as a password, so you're in' isn't very satisfying. It's not a much of a reflection of the PCs great skill, except possible to find out where some idiot did something dumb. If you want to have a story about breaking encryption, it's better to do stuff like find the right buy to rubber hose attack, break into someplace to steal the decryption key, plant cameras to watch the guy enter his password, or something like that. It also has the advantage of involving more players. ----------------- [edit] Using the 'guessed' plain text attack, it's apparently possible for a modern PC to break 3 rotor Enimga in a matter of seconds, and 4 rotor Enigma in a matter of hours. What's a 'guessed' plain text attack? You assume your message contains some bits of known text, for example 'Heil Hitler' and then check if your potential break has that text in it. Part of the reason why the British were very good at breaking Enigma is that they knew the general message formatting and vocabulary, so we able to make very good 'guesses' as to the message contents. Just brute forcing the entire keyspace of a 3 rotor machine seems to take a modern PC 'hours to days' and brute forcing a 4 rotor machine is 'around two orders of magnitude more difficult' (i.e. weeks to months) But WW2 was the earliest days of computing related math and technology, and considerably better encryption techniques have been developed since then. In addition, one of the oldest (one time pads) are still unbreakable, though it turns out that generating 'good' one time pads is a bit of a difficult problem and robust solutions were generally not available until after WW2. Quote Link to comment Share on other sites More sharing options...
mrinku Posted July 31, 2017 Report Share Posted July 31, 2017 Another thought I had this morning might be to use Computer Programming as a Power and add Ranged (maybe improved to LOS), to represent a superpower to access and reprogram normal computer systems. Unrealistic for a radio hacker (i.e. buy high range radio hearing instead and start guessing passwords), but might suit a 25th Century Quantum AI or a technomage. (Note this would not confer Mind Control or Telekinesis effects. Just allow reprogramming using the existing rules for when a character has gained access to a computer). Quote Link to comment Share on other sites More sharing options...
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