<s>
TKEY	B-Protocol
(	O
transaction	O
key	O
)	O
is	O
a	O
record	O
type	O
of	O
the	O
Domain	B-Protocol
Name	I-Protocol
System	I-Protocol
.	O
</s>
<s>
TKEY	B-Protocol
RRs	O
can	O
be	O
used	O
in	O
a	O
number	O
of	O
different	O
modes	O
to	O
establish	O
shared	O
keys	O
between	O
a	O
DNS	B-Protocol
resolver	O
and	O
server	B-Protocol
.	O
</s>
