Abstract: Alignment and valid points selection of electromagnetic leakage curves are important research direction of information security. For the problem of curve excessive shifted, a new method of curve alignment is proposed, whose name is bimodal correlation alignment method. The method effectively controls the curve excessive shift, and also achieves a precise alignment result. It is proposed to use independent component analysis (ICA) to select valid points. By the method of ICA, unknown source signals are obtained from electromagnetic leakage curves for classification analysis. ICA, principal components analysis(PCA), ICA-PCA, and PCA-ICA are adopted for dimensionality reduction. The classification result is got by support vector machine (SVM). It shows that success rate of ICA and PCA-ICA grows rapidly with the increase of the dimensions. PCA-ICA is the best, ICA is better, whice the worst is ICA-PCA, in the dimensionality 10 to 100.In the dimensionality 100 to 900, the success rate grows mostly like a line with the increase of the dimension.