Based on ciphertext index and aiming at practical application on encrypted database,the paper designs a new ciphertext index by combining binary tree ciphertext index with B+ tree index.

• 在密文索引的基础上,针对实际密文数据库的应用,将二叉树密文索引和B+树索引相结合,设计了一种新的密文索引,并介绍了其查询方法,分析了其查询效率及安全性