Side Channel Attacks (SCAs) are a serious threat against security of cryptographic algorithms. Most of the countermeasures proposed to protect cryptosystems against these attacks, are efficient but present a significant area and power consumption overhead. The registers being the main weakness of cryptosystems, the source of leaks the more easily exploitable, we proposed a secure DFF which reduces leaks. In this paper, we present this countermeasure which considerably increases the robustness of cryptographic algorithms against side channel attacks. Moreover, the area and power overhead of our secure DFF in a cryptosystem is attractive.