With all due honour to the exploits of those clever-clogs at Bletchley Park and the intrigue that surrounded the use of their ULTRA, decryption (and SIGINT in general) don’t easily make for a variety of good RPG adventures. You can devise some adventures that make good use of remote cracking and the security discipline that opposes it, but there is a persistent danger that if you make it realistic it is slow and puts the key actors in secret rooms remote from interaction with NPCs¹, while if you make it cinematic without letting institutions respond realistically to it it becomes a setting-wrecking superpower. So in Flat Black I want decryption of intercepted broadcasts not to be a common thing.
It seems to me that I have two options. Either
- Nobody much broadcasts a lot of encrypted secrets or transmits them along cables that might be tapped, because they know that anything they encrypt might be decrypted. There are therefore adventures to be had smuggling and intercepting physical deliveries of secure material.
- Most everyone routinely broadcasts encrypted secrets or transmits them through networks, but you can’t crack their encryption so you have to subvert their people or infiltrate their premises to get a look at their source texts or decrypts.
The two possibilities suggest two different sorts of adventure, one involving either carrying a message or intercepting a courier, the other involving infiltration by stealth or social engineering, to steal records or codebooks.
What if I say that everything is crackable except for a one-time pad? Do I then get both kinds of adventure because of couriers trying to deliver stacks of pads?
¹ Once upon a time I ran a Flat Black adventure for a very small group of PCs who were working for some sort of Imperial intelligence outfit, and that involved them monitoring the mysterious activities of some shadowy figures on a world that had such development that iron-hulled ocean-steamers were a marvel. The shadowy figures had a ship that I based on the idea of Isambard Kingdom Brunel’s SS Great Eastern, which they were using to operate a bathysphere at great depth and recover something from the bottom of the ocean. The PCs thought that they were being very clever to hide below the horizon and use an aerial remote probe to set the ship’s main deck and principal cabins with bugs and surveillance devices, but (a) the oppo did not conduct any “As you know, Jim” conversations, and (b) when the shit hit the fan the PCs were fifteen minutes away and unable to intervene. Fortunately the shady characters weren’t interested in the Eichberger drive on the sunken pirate ship, but the priceless AI running on that ship’s computers was killed by the secret police.
Think once. Think twice. Get on the ship and interact with NPCs!