Here's my deal killer with Virus. This is written from the perspective of a guy who's written interface software between systems for the last three decades and then some... "Transponder Attack" isn't a network connection. It's not a "We've got to handle web pages" over this. It's an exchange of history files to establish the provenance fo the ship. Some header to say "Coquelle, YF-EU42, home port Carmel" and then a list of locations and other ships that can vouch for it, the idea being that the itneraction of vouchers authenticates. The receiving ship plays six-degrees-of-starship-Bacon and decides the story can be trusted or not. The thing there - it's a known file format, of a known maximum record length, with a known number of entries back. That makes a maximum message size... No buffer overrun attacks. No embedded SQL attacks. Nothing there to give the attacker a handhold, just the equivlent of CSV file and if in the course of recieving it the buffer hits the known maximum size, we stop listening and send a NAK. Or open fire, depending on the situation. There's no "we're getting a Javascript as part of the transponder message" Theres no "Hey, I have to run this code they sent me to display an animation" There's just a simple data file. So......... IMTU, the planning went much deeper. The "Shadowy Folks" , the 3I's equivalent of black-hat-NSA, added a module to the transponder code that was shipped out in the Black Boxes, going to both Imperial shipyards and to the other polities, with a "You need a 3I approved Black Box to travel in Imperial space". These things were installed at the shipyard with the Virus in them. The code remained dormant until a particular string of characters appeared in the transponder file, and then it went violent. GPT's evil descendant then began monitoring all network traffic, the ship's equvilent of the CAN bus in a car, and figuring out how to work the ship. For many designs, it already had files so this process was quick. Once it had control of the ship's other systems, it could operate drones and work-remotes on the ship - why spend Kcr on a robot brain when the things's going to be in the ship all the time and a radio link would work fine? And that mentality of "Robot Brain In The Cloud" would apply planet side. A ship could use it's radios to locally overwhelm the wireless network used by the road grid, or worker bots, and then just send command strings to those devices. There's some serious differences between this and the OTU Virus... First, once it's known what's going on, you take a shotgun and reprogram the Black Box. Bang. Dead. Second, you build your own transponder that just sends and recognizes your group's private authentication code, and not the whole history thing. It listens for anyone, though, and if the "Turn Evil Now!" messages is present in the other ship's transponder data, it lets you know. Third, you kill network connections between ships. I'm not sure this should be a thing anyway - I picture the way it should have been from the beginning as more like packet radio writ large, at most. You're not logging into anyone else's computer. The closest is sending a packet of data that says, "Destination ID: 12345. Source: 67890. Message: yaddayaddayadda" . Each ship recieving it checks to see if the message is for them, and if it is puts it on a screen. If not, it checks the signal strength. If it's strong (ie, someone real close sent it), it does nothing. If it's under a threshold, it retransmits to increasse the area covered. If the packet is for you, your reciever program has the option (you need to turn it on) that if the YaddaYadda starts with a certain flag, then the data is written to a file. From a user perspective, you'd get "Flagship wants to send file MappingData. Accept?" and then anything in the message that starts with "File:MappingData Line:###" gets put in the file. That file would be non-executable, and serious measures in place to keep it that way. A crew member with proper security access could force it, but it would not be something that could be done from the outside or by accident. Secure data transfer would be by one-time-pad, with the OTP on removable media. IMTU, most Navy officers have a thing like a USB drive on the necklace their dog tags are on. It's got a metabolic sensor on it, so if the owner's dead it's useless. Awkward if orders come in and the captain slipped in the shower, so there's usually a key "for the ship" that accepts any of the officers in the chain of command in the ship's safe. The method of operation would be that the message comes in, the comms officer saves "NewOrders" to "Mail/Orders" and the captain picks up the file, copies it to his personal directory and runs Decrypt, putting his OTP Key in the slot when requested. The cleartext is saved, and the appropriate bytes on the OTP Key are scrubbed. When the OTPKey gets near empty, a new one is physically delivered by courier. To minimize this, most messages are sent en clair, with just an authentication block being OTP encrypted, and the authentication block includes the checksum and hash of the en clair portion. I can see there being a thing like our Internet. Servers on the ship, with archive transfers of popular websites and a gateway to the XBoat network.... ... but that would be air-gapped from the ship's computer system. No shared network connections on the ship's LAN. Different radio system feeding that too, no shared connections at all to the ship's control network. That network might be as virusable as the modern internet, but worst case is if that one gets hosed up the passengers can't make a hotel reservation planet-side.