First, produce key with RSA and construct a binary tree, then traverse the binary tree to produce new keys. And there must be a certain key to encrypt data with all the other encoding methods.

By careful researches of the traversal of binary tree, a new method of traversing binary tree is brought forward, which is able to solve the problem of traversal of binary tree.

This paper goes deeply into such tree's structure using both depth search and breadth search, and gives recursive relationship separately.