Document Type : Technical Paper


Shahid Beheshti University Faculty of Computer Science and Engineering Tehran, Iran


The template attack is one of the most efficient attacks for exploiting the secret key. Template-based attack extracts a model for
the behavior of side channel information from a device which is similar to the target device and then uses this model to retrieve
the correct key on the target victim device. Until now, many researchers have focused on improving the performance of template
attacks ,but recently, a few countermeasures have been proposed to protect the design against these attacks. On the other hand,
researches show that regular countermeasures against these attacks are costly. Randomized shuffling in the time domain is known
as a cost-effective countermeasure against side-channel attacks that are widely used. In this article, we implemented an actual
template attack and proposed an efficient countermeasure against it.We focus on the time shifting method against template attack.
The results show that template attack is very susceptible to this method. The performance of attack on an AES algorithm is
considerably reduced with this method. We reported the analysis results of our countermeasure. The performance of the attack
can be determined according to various criteria. One of these criteria is the success rate of the attack. According to these results,
template attack will be hardened significantly after the proposed protection such that the grade of the key recovery increases from
1 with 350K traces in unprotected design to 2100 with 700K traces in the protected circuit. This security improvement gains in the
cost of about 7% delay overhead.