OTPs are vulnerable if you do the one thing that you're not supposed to do with a OTP, namely reuse the bits.
YES. "One time" means "ONE TIME". Use once and destroy.
The one time pad must be random, generated by a true random process. Not pseudorandom.
Not generated by an algorithm. Not generated from a shorter key. Not reused. Not generated by humans hammering on typewriters (see Venona).
One time keys are used for some crucial point to point links. Embassy to foreign ministry, higher military headquarters to high command, or spy to HQ.
> One time keys are used for some crucial point to point links. Embassy to foreign ministry, higher military headquarters to high command, or spy to HQ.
I am very skeptical this actually used in practice anywhere. The one-time pad is prone to side-channel attacks, since sharing the secret key(s) is such a nightmare. Putting people on planes flying around the globe with bags full of keys or having long lists of keys lying around is a security nightmare. Using an asymmetric encryption scheme is in practice a lot safer.
Declassified NSA documents describe some of the systems.[1] Early systems used paper tapes for the key. One of the features was a tape slitter, so the tape could only be used one time before it was cut in half. Systems with floppy disks have been advertised. Mils Electronik sold one time key systems from the 1950s until 2017.[2] Early systems used paper tape, later systems were electronic and stored the keying material on PCMCIA cards.
YES. "One time" means "ONE TIME". Use once and destroy. The one time pad must be random, generated by a true random process. Not pseudorandom. Not generated by an algorithm. Not generated from a shorter key. Not reused. Not generated by humans hammering on typewriters (see Venona).
One time keys are used for some crucial point to point links. Embassy to foreign ministry, higher military headquarters to high command, or spy to HQ.