CoreDES

6

v4.0

Encryption

To begin the process of encrypting data, the following

inputs are set:

1. K[1:64] is set to the cipher key (ck1 in Figure 6) to

encrypt the data.

2. D[1:64] is set to the plaintext data (d1 in Figure 6)

to be encrypted.

3. ED is set to logic '1'.

4. EN is set to logic '1'.

After 16 clock cycles of the EN input being held

continuously at a logic '1' value, the QVAL signal will

transition from logic '0' to logic '1' and remain valid for

one

clock

cycle,

indicating

that

valid

ciphered

(encrypted) data (shown as q1 in Figure 6) is available on

the Q[1:64] outputs.

Figure 6 • Example Encryption Sequence

CLK

K[1:64]

D[1:64]

ED

EN

1

2

3

4

5

6

7

8

9 10 11 12 13 14 15 16

cycle

Q[1:64]

QVAL

q1

ck1

d1

Don't care

Undefined