February 26, 2002
Practical Aspects of Modern Cryptography
42
Diffie-Hellman Key Exchange
n
Alice
n
Randomly
select a large
integer
a
and
send
A
=
Y
a
mod N
.
n
Compute the
key
K =
B
a
mod N
.
n
Bob
n
Randomly
select a large
integer
b
and
send
B
= Y
b
mod N
.
n
Compute the
key
K =
A
b
mod N
.
n
B
a
= Y
ba
= Y
ab
= A
b