In this paper, we set up trapdoor one way functions using diophantine equations of k degree (2Xk) with more than two variables, using these functions a new public key cryptosy-stems can be set up.

• 运用多元k次(k是奇数)丢番图方程构造了一类陷门单向函数；用它们可以建立一种新的公开钥密码.