摘要： RSA加密算法是目前使用较多、安全性高的一种非对称加密算法，在实际应用中要使该算法有较高的防破解强度，在大素数的选择上是有要求的。文章给出了选择高质量的大素数的有效方法，并对一些不当的选择可能造成的泄密给出了相应的证明。

关键词: 大素数, RSA算法, 安全性, 攻击

Abstract: RSA encryption algorithm is a popular unsymmetrical encryption with high secure character. There are some special requirements in the selection of the large prime number in order to prevent the decryption. An efficient method has been introduced, which can be used to select the large prime numbers, and the some reasons which cause lower security by selecting incorrect prime number have been proved.

Key words: Big primes, RSA algorithms, Security, Attack