Security Issues in QCA Circuit Design - Power Analysis Attacks - Field-Coupled Nanocomputing: Paradigms, Progress, and Perspectives - page 199

1 x 10 −3

SF=0.6
SF=1.2
SF=1.8
SF=2.6
SF=3.0

0.9

0.8

0.7

0.6

0.5

0.4

0.3

0.2

0.1

0

0 2000 4000 6000 8000 10000 12000

Number of Samples in Time Domain

Fig. 3. Clock signals under smoothing factors (SF) of 0.6, 1.2, 1.8, 2.6 and 3.0.

14

γ /E k =0.2
γ /E k =0.4
γ

12

/E k =0.6

10

γ /E k =0.8

γ /E k =1.0

8

6

4

2

0

10 −4 10 −3 10 −2 10 −1 10 0

Clock Smoothing

Fig. 4. Total power consumption in a QCA cell under various clock smoothing levels for
different tunelling energy γ values ( T =5 . 0 K). Adiabaticity of the switching process
is controlled by smoothness of the clock. The horizontal line show the upper bounds
for each case.

The second part happens when the driven cell changes state ( G − to G + ), and
the third part is produced by changing the clock from high to low ( γ H to γ L ),
which latches the cell to the new state. The first and third parts of the power
consumption occur even if there are no changes to the cell's polarisation as shown