Horizontal collision correlation analysis, in short HCCA, imposes a serious threat to simple power analysis-resistant elliptic curve cryptosystems involving unified algorithms, e.g., Edwards curve unified formula. This attack can be mounted even in the presence of differential power analysis-resistant randomization schemes. In this paper, we have designed an effective countermeasure for HCCA protection, where the dependency of side-channel leakage from a school–book multiplication with the underlying multiplier operands is investigated. We have shown how changing the sequence in which the operands are passed to the multiplication algorithm introduces dissimilarity in the information leakage. This disparity has been utilized in constructing a minimal cost countermeasure against HCCA. This countermeasure integrated with an effective randomization method has been shown to successfully thwart HCCA. Additionally we provide experimental validation for our proposed countermeasure technique on a SASEBO platform. To the best of our knowledge, this is the first time that asymmetry in information leakage has been utilized in designing a side-channel countermeasure.