中文摘要：

在许多实际的应用场景中，当用户需要获取敏感数据时，需要判断该用户是否满足某些“流程”的要求．现存的加密方案不能有效应用到以上场景中．为了解决这一新问题，提出了一种新的加密原语：基于流程的加密（process based encryption．简称PBE），并把PBE分成两种类型：密钥策略的PBE（KP-PBE）与密文策略的PBE（CP-PBE）．运用双线性映射与线性秘密共享协议的工具，给出了一种KP-PBE的构造方法．随后，把KP-PBE方案与传统属性加密进行对比，指出在描述流程数量方面，KP-PBE与传统属性加密方案存在数量级的差异，从而体现了KP-PBE方案在描述流程方面的优越性．最后，在选择性安全的模型下，证明了该方案的安全性．

英文摘要：

In many applications, when a user needs to access sensitive information, it is a usual requirement to authenticate whether or not the user satisfies certain processes. Existing encryption schemes are not applicable for this scenario. To adderess this problem, a new cryptography primitive called process pased encryption （PBE） is presented. The application scenario of PBE is demonstrated. PBE is classified into two categories： Key policy process based encryption （KP-PBE） and ciphertext policy process based encryption （CP-PBE）. A KP-PBE scheme is constructed utilizing the tools of bilinear map and linear secret sharing scheme （LSSS）. Compared to conventional attribute based Eecryption （ABE）, the performance of KP-PBE is much better on describing processes. Finally, the security of KP-PBE is proven under the selective security model.