The Keyboard That Could Phone Home
An anonymous reader writes "University of Pennsylvania researchers have developed a keylogger they call the JitterBug that can modulate passwords or other information into normal traffic by adding imperceptible delays to keypresses as people use keyboard and network-intensive apps like telnet and remote desktop. The idea is that the delays in keypresses cause delays in packets, and data can be encoded in those delays. There's no software or extra network activity that the victim can see, but anyone who can see the traffic (even if it's encrypted) could grab the data. Here's the scary part: the researchers say that it could be manufactured into a keyboard, making these keyloggers widespread and virtually undetectable."
Just enable (as it's usually disabled for things like SSH) Nagle's algorhitm, and it should destroy most of the timing information.
For those who don't know, it's a TCP optimization that buffers data until there's a packet worth of data, or an ACK is received for the last packet sent, so that writing 1 byte of data into a socket doesn't immediately result in sending a packet with 40 bytes of overhead, and 1 byte of data.