Up till now, Baptista's cryptosystem scheme and its improved versions can not effectively solve some problems, such as long cryptographs, slow encryption speed, non-uniform distribution of cipher text, lower security and so on. 目前为止Baptista密码方案及其改进版本仍没有很好地综合解决密文长度较长、加密速度较慢、密文分布不均匀和安全性不高等问题。