<s>
The	O
Navajo	B-General_Concept
I	I-General_Concept
is	O
a	O
secure	O
telephone	O
built	O
into	O
a	O
briefcase	B-Application
that	O
was	O
developed	O
by	O
the	O
U.S.	O
National	O
Security	O
Agency	O
.	O
</s>
<s>
It	O
uses	O
the	O
linear	B-Algorithm
predictive	I-Algorithm
coding	I-Algorithm
algorithm	O
LPC-10	O
at	O
2.4	O
kilobits/second	O
.	O
</s>
