There is a secret ship and it is used by pirates as a recharging point. It has a nuclear reactor as a power source and other ships are using electricity. Let's assume in this world stealth technology is more advanced then detecting technology, so the only way to find this secret ship is to know its exact location.

This is a pirate ship, so the pirates must have an opportunity to find it and recharge their accumulators, but at the same time, good guys should not have this opportunity. The secret ship is slow, so if good guys getting its current location, they are sending a plane and no more secret ship.

For now, these are my ideas:

  1. The location info should be sent encrypted by request.
  2. Single-use keys to decrypt.
  3. Keys are obtained through visiting the secret ship

Problems which I am trying to solve:

  1. How is broadcasting organized? This is happening in the near future, so it is possible to have the internet(by satellites) in the ocean, but the connection will blow the cover. Maybe it is the radio, but this will blow the cover even more.
  2. How to protect the secret ship from betrayal. In case the one with the key will give it to the good guys. How the secret ship can verify it is the same person this key was given to?

The limitations and freedom points:

  1. The satellites are not on geostationary orbits, they are Starlink type or similar. If there is a way to alter their architecture so that they won't blow the secret ship's cover it is ok.
  2. There is no magic in this world and no aliens.
  3. Fossil fuels became recently very expensive, so there are not so many planes flying and everything uses electricity as a power source.
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    $\begingroup$ Is there a lot of legitimate radio traffic going back and forth between non-pirate ships etc.? $\endgroup$ – A. I. Breveleri Jan 9 '20 at 19:51
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    $\begingroup$ I think no. As I know there is not a lot now, so I think there is no reason why in the near future it should be more. $\endgroup$ – FrogOfJuly Jan 9 '20 at 20:04
  • $\begingroup$ As an imaginary Navy admiral tasked with eradicating piracy (along with many other tasks), seems like simply offering a large reward will eventually cause a pirate (or a family member) to squeal enough for me to locate and track the pirate mother ship. Simple, direct, and likely cheaper than the technological alternatives. $\endgroup$ – user535733 Jan 9 '20 at 20:18
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    $\begingroup$ Though it rather spoils your premise, synthesis of hydrocarbon fuels from air and water is a good way to store and transport energy. It lets you operate aircraft, and it lets you separate your pirate generator (the ship with the reactor) from the fuel (tanks of eg. dimethyl ether or methanol or ammonia) which can be dropped safely a long way from its source ready for collection. $\endgroup$ – Starfish Prime Jan 9 '20 at 20:40

This requires public key cryptography. It will allow the base ship to sign messages... no one will be able to forge them. It will allow them to encrypt as well, and only those who have the other key will be able to decrypt, so the broadcast will only be able to be listened in on by a limited group.

They will use burners, so to speak (but not cell phones... not many sells-for-cash convenience stores in the Pacific or whereever). They will be buoys. Cheap ones, they only have to work for a few days. They will be dropped overboard, and programmed to broadcast 48 hours later (a message prepared in advance, for where the ship expects to be).

Finding the buoy is useless, except as denial of service if you can get to it before the broadcast (and there might be more than one). Afterward it offers no clues. No one is coming to where the buoy is found, so you can't wait in ambush. And if the crypto keys are seized, they can be revoked and new ones issued. Might be occasions where the pirates show up and the base ship isn't there... they feared someone or another had been compromised and that authorities would intercept them at the rendezvous. In such situations, there is a emergency rendezvous location all know to go to, but that was never written down. New keys are exchanged in person there.

This becomes a race to capture the pirates and seize their keys before someone can worry that they've been captured. And since the meetup is 48 hours after the broadcast, that will be tricky even if they can decode it. Their next best bet is to torture one of the pirates into giving up the emergency rendezvous points if that's allowed. But with sufficiently fanatical pirates willing to commit suicide, that won't be an option either.

Hell, even finding the SD card with the crypto might be difficult enough. It's one thing to toss an apartment in some city, but to do that on a ship at sea? You can't exactly drill holes looking for hidden compartments.

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    $\begingroup$ The buoy idea is great. I think it will do the thing $\endgroup$ – FrogOfJuly Jan 9 '20 at 20:21
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    $\begingroup$ The next best bet is to tag suspected (or known) pirate ships with location trackers. Torture is messy and unreliable. $\endgroup$ – Starfish Prime Jan 9 '20 at 20:36
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    $\begingroup$ +1 delayed action buoy, brilliant. $\endgroup$ – A. I. Breveleri Jan 9 '20 at 22:29
  • There is no credible way to prevent betrayal from pirates who are supposed to visit the recharging ship. At the very latest, they can use radio to transmit the position when they finally see the recharging ship. If they are told the exact position before they reach it, they can broadcast it then.
  • The same applies to agents in port who tell the pirates where to go, etc.
  • One possible option to delay the possibility of betrayal is to sent the pirates to a first meeting point, where they are checked and sent on to the next meeting point, and so on. Of course this will waste energy as the pirates cannot sail the best course.
    The recharging ship relies slightly less on the pirates, but it turn it depends on having agents somewhere to check pirates and decide to pass the next step of the secret.
  • A variant, the pirates go to a meeting point and take on pilots. Then the pirates must leave the bridge of their own ship and the pilots navigate it.
  • Another option would be to use smaller ships as "energy tankers." These small ships recharge from the mothership, then go to a meeting point and charge the pirates in turn. Only the "energy tankers" know where the mothership can be found, never the pirates.
    Problem: The "energy tanker" crew could be made to betray the mothership.

But all these bullet points are just highlighting the problem: If people are supposed to find the reactor ship, people can find the reactor ship. And there are interrogators who can make (almost) anybody talk.


I'm going to offer a bit of a frame challenge here, because if your secret ship has a nuclear reactor there is absolutely no reason for it to be slow.

Everybody is running off electrical motors for propulsion, but your secret ship has a nuclear reactor instead of batteries which generally means it has MUCH more power available and doesn't have to worry about running out of battery. Even if your secret ship is a nuclear submarine (which honestly is the most plausible scenario), it's still going to be faster than almost anything else.

So, the simple solution to your problem is that your secret ship is a submarine, and the way you keep it secret is that the pirates don't go to the submarine, the submarine comes to the pirates. Somewhere different every time, and the pirates are just told to sail somewhere and when the submarine crew decides everything is kosher it surfaces, recharges the pirates, and leaves. The pirates will never know exactly where or when the sub will show up to recharge them, and even if the good guys set a trap, it'll have to be a REALLY good one or the submarine will detect it and just run away.

  • $\begingroup$ Sorry but the submarine is not an option( I thought of that, but there is no way. The thing about speed is very true, but it does not apply to jets. Even if the jet fuel is expencive the militaries are the last ones who will run out. $\endgroup$ – FrogOfJuly Jan 9 '20 at 20:08
  • $\begingroup$ @Kirill even if it's not a submarine, there's still no reason for it to be slow though. Anything with a nuclear reactor is going to have a huge advantage in mobility over anything that just runs off batteries. $\endgroup$ – Morris The Cat Jan 9 '20 at 20:11
  • $\begingroup$ The problem with jets is still relevant even for the ship with nuclear power source $\endgroup$ – FrogOfJuly Jan 9 '20 at 20:17

Pirates take a one time pad when they leave the ship. The ship has established several small radio broadcasting towers on a variety of scattered islands. At a previously set time the ship chooses a location and broadcasts it using these island transmitters. The pirates show up to this location, are vetted to ensure that they aren't being trailed and then are escorted to the location that the main slow ship is-- possibly in a strategically advantageous position, like through a narrow pass which would allow for cover from overhead surveillance and be easily defendable from attacking forces.

  1. The ship does not broadcast its message openly. It connects to PTP-based network like Tor which obscures the source of the message. There is no way for the authorities to link a particular satellite access session to the pirate ship.

  2. Stolen keys is definitely a problem. For this purpose, Multi-factor authentication was invented. The user would have not just one key, but a number of them (personal password, fingerprint, phone number etc.) and they all should match so the user can be authenticated. Of course, all of those keys can be compromised, but this is more secure than a single key.

  • $\begingroup$ The problem with something like Tor is that you still need to connect to an entry node into the network, and if you do that via a third party (eg. a satellite network) your location can be identified, given a little time. $\endgroup$ – Starfish Prime Jan 9 '20 at 19:23
  • $\begingroup$ @Starfish Prime it can be only either if the entry node is compromised, or if overall Tor traffic is very low, and you can link particular access session to an outgoing event (which doesn't even have to happen immediately). $\endgroup$ – Alexander Jan 9 '20 at 19:27
  • $\begingroup$ The connection to the node is something that the operators of the satellite network will be able to see. Correlating encrypted network connections from ocean areas with little legitimate traffic against satellite imagery tracking wakes is likely to start tipping the balance. $\endgroup$ – Starfish Prime Jan 9 '20 at 19:37
  • $\begingroup$ @Starfish Prime so yes, this is a "very low traffic" scenario. In that case, pirates may want to add a private server between the satellite network and PTP network. But if the pirate ship is in a region where no ships are supposed to be, that's indeed a problem. The internet access session has to be open from a different location. $\endgroup$ – Alexander Jan 9 '20 at 19:44

While many of the cryptology based answers are intriguing, to me this looks like a job for steganography, not cryptology. A well-paid Confederate broadcasting legitimate short-wave (global reach) broadcasts hides the encoded coordinates in something obvious, but with meaning only to the pirates, like the order of a song playlist. Select artists in a select order give the coordinates of where the power ship will be in 48 hours time.

Alternatively, if the tech exists, the, the power ship can beam a laser to a specific point on the Moon's surface that blinks off-and-on at a rate to fast to be seen by the human eye, flashing out on Morse code the future rondevou coordinates, only those who know when and where to look on the Moon's face will get the signal. For good measure, the signal could be encrypted, and include the time/Lunar location of the next burst transmission.


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