Design Automation for Embedded Systems

, Volume 12, Issue 3, pp 207–220

Path switching: a technique to tolerate dual rail routing imbalances


DOI: 10.1007/s10617-008-9017-z

Cite this article as:
Baddam, K. & Zwolinski, M. Des Autom Embed Syst (2008) 12: 207. doi:10.1007/s10617-008-9017-z


Dual Rail Precharge (DRP) circuits, which are theoretically secure against differential power analysis attacks, suffer from an implementation problem: balancing the routing capacitance of differential signals. To solve this, four proposals have been put forward: Divided Wave Dynamic Differential Logic (DWDDL) (Tiri and Verbauwhede in DATE ’04, pp. 246–251, [2004]), FatWire (Tiri and Verbauwhede in Cardis 2004, pp. 143–158, [2004]), Backend Duplication (Guilley et al. in Lecture Notes in Computer Science, vol. 3659, pp. 383–397, [2005]) and Three Phase Dual Rail (Bucci et al. in Lecture Notes in Computer Science, vol. 4249, pp. 232–241, [2006]). Of these, three (DWDDL, FatWire, Backend Duplication) proposals alter the routing mechanism of Standard Place and Route tools, which in turn introduces an additional step. The other proposal introduces a third phase which reduces the system’s performance. In this paper we propose a new countermeasure, Path Switching, to address the routing problem in DRP circuits. From SPICE simulations we show that our proposal does not reveal the secret key for up to 300,000 traces, an increase of 75 times over normal Dual Rail circuits and 3000 times over normal single rail circuits.


DPA Smart card security Dual rail circuit Path switching 

Copyright information

© Springer Science+Business Media, LLC 2008

Authors and Affiliations

  1. 1.Electronics Systems and Devices Group, School of Electronics and Computer ScienceUniversity of SouthamptonSouthamptonUK

Personalised recommendations