🚀 go-pugleaf

In article <2120002@hpnmdla.HP.COM> darrylo@hpnmdla.HP.COM (Darryl Okahata) writes:
>>  You use ordinary phrases to mean other things,  
>>  And you use a shared, trusted codebook ( translation lookup-table),
>> Then you could use unsecure channels to communicate securely.
>
>     In practice, it is extremely difficult to have a codebook that
>produces a conversation that makes sense and flows smoothly, and, if you
>do not have a coded message that makes sense and flows smoothly, it will
>stand out a like a sore thumb to trained eyes.

It can be done, by making the "codes" sufficiently high-level.  You can
use what Heinlein dubbed "idea code", in which the actual wording does
not matter at all -- the meaning is encoded by the content.  For example,
a lament about the high cost of art supplies means "you are believed to
be under suspicion" while an inquiry about Aunt Katy's health means
"you are believed to be in the clear".  This does make for bulky messages
if you're trying to send anything complex, though.
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