This message will self-destruct....

[Tom Taggart]

See:

http://vanish.cs.washington.edu/

According to the proposal, this software allows messages to be encrypted, but be viewed for a period of time. After that, the message turns into gibberish.

[genlock]

An enciphered message used with vanish would make code breaking impossible.

[Jet Black]

What I think about thax iz heg thgs dhet dght ght ght fgnwhr!

[genlock]

A short term fix for cryptanalysis would be to print all messages.
Very impractical considering the volume.
Military circuits have used constant traffic flow for 50 years or so.
At least since the KW-26/tsec. That was with 5 level baudot teletype.
So the best method of obtaining information is torture.
Start breaking bones at the big toe and progress upward.
scapolomine hydrachloride may work.
Pain never fails.