US 11,750,361 B2
Clock period randomization for defense against cryptographic attacks
Donald Stark, Palo Alto, CA (US)
Assigned to Google LLC, Mountain View, CA (US)
Filed by Google LLC, Mountain View, CA (US)
Filed on Feb. 16, 2021, as Appl. No. 17/176,554.
Application 17/176,554 is a continuation of application No. 15/436,489, filed on Feb. 17, 2017, granted, now 10,958,414.
Claims priority of provisional application 62/298,842, filed on Feb. 23, 2016.
Prior Publication US 2021/0194667 A1, Jun. 24, 2021
This patent is subject to a terminal disclaimer.
Int. Cl. H04L 9/00 (2022.01); G06F 7/58 (2006.01)
CPC H04L 9/002 (2013.01) [G06F 7/582 (2013.01); G06F 7/588 (2013.01); H04L 9/003 (2013.01); H04L 9/004 (2013.01); H04L 2209/08 (2013.01); H04L 2209/12 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A system comprising:
a processor configured to be driven by a randomized clock signal; and
a variable clock configured to generate the randomized clock signal from a received input clock signal, the variable clock comprising:
a variable delay generator comprising a phase interpolator configured to produce a variable delay amount;
a fixed delay generator configured to generate a fixed delay amount;
circuitry configured to combine the fixed delay amount and the variable delay amount to create a combined delay amount; and
an output configured to generate the randomized clock signal responsive to the combined delay amount elapsing since receiving the input clock signal.