An Optimized Cross Correlation Power Attack of Message Blinding Exponentiation Algorithms

The message blinding method is the most efficient and secure countermeasure against first-order differential power analysis(DPA).Although cross correlation attacks(CCAs) were given for defeating message blinding methods,however searching for correlation points is difficult for noise,misalignment in practical environment.In this paper,we propose an optimized cross correlation power attack for message blinding exponentiation algorithms.The attack method can select the more correlative power points of share one operation in the modular multiplication by comparing variances between correlation coefficients.Further we demonstrate that the attack method is more efficient in experiments with hardware implementation of RSA on a crypto chip card.In addition to the proposed CCA method can recovery all 1024 bits secret key and recognition rate increases to 100%even when the recorded signals are noisy.

现行投资项目财务评价的局限性分析

一、现行投资项目财务评价的局限性 投资项目财务评价的可行性主要评判指标是内部收益率是否高于其行业基准收益率和投资回收期能否满足其行业基准投资回收期。均满足,则投资项目财务上可行。 我们清楚,税后利润高则内部收益率高、投资回收短;税后利润低则内部收益率低、投资回收长。税后利润计算时假设项目在执行中产品产量、生产成本、产品价格为确定值,而客观实际并不完全如此,则影响税后利润计算结果的可靠性。