
It is completely clear. You have to assume that each byte that was encrypted
by this 'Clipper Chip' has been compromised. 
Some people wondered, why Denning, Hellman and others did not respond,
when asked what would be done about such compromised phones, or if
compromise could not be restricted in time. (I did too) Let us just assume
that a) They do not know and b) Those who know don't tell and c)
They do not care. It seem's to be an 'Other Person's Problem' ...

 gec