UW Computer Security Research and Course Blog

According to Scientific American, the US Navy is considering to deploy a new technology, Deep Siren, to improve communication to and from submerged submarines. As of now, submarines have to be no deeper than 60 feet and towing a floating antenna behind them before they can communicate with the outside world. This makes the submarines far less agile and much easier to detect. The Deep Siren System will theoretically allow subs to communicate at any depth and speed.

The Deep Siren system, developed by RRK Technologies, consists of disposable buoys that convert RF signals from satellites into acoustic signals that are then broadcast up to 175 miles away. The submerged submarines, moving at any depth and speed, receive these signals via their sonar system. The buoys are approximately 5 inches in diameter and 3.5 feet long making it possible to eject them out of the subs trash disposal. They can stay afloat for about 3 days.

Assets

• The privacy and integrity of the communications.
• The encryption scheme that the Navy uses as it is probably an NSA secret.
• The location of submarines.

Potential Adversaries

• Foreign governments. Other governments would certainly be interested in what US submarines were up to.
• Developers at RRK Technologies.

Potential Weaknesses

• The buoys are not guarded or retrieved, leaving part of the system exposed to potential adversaries to reverse engineer part of the technology, including the encryption algorithm.
• The signal is broadcast from the buoy. If adversaries are attentive, they could triangulate the location of these buoys and either remove them from the area (by either destroying or collecting them) or learn where submarines have been and perhaps where they are going.
• It seems like it would be easy to cut availability or block communications by barraging the buoys with acoustic and RF signals.
• Also, depending on the amount of these buoys released, this could further the hatred for the US by other countries as all these buoys wash up on their shores or cause other environmental problems.

Potential Defenses

• A strong encryption scheme, courtesy of NSA.
• Anti-tampering devices to deter reverse engineering.

Risks

The risk that these weaknesses expose is potentially high. The signals that are broadcasted to and from submarines would be easy to intercept or eavesdrop, yet with a strong encryption algorithm, these communications could theoretically be kept secret and safe.

Conclusion

Deep Siren seems very similar to wireless networks in that the signals are broadcast to every one in the area. It seems to me that Deep Siren would be vulnerable to the same type of attacks against wireless networks. Hopefully it doesn’t get to the point where there is a naval equivalent of war driving.