Privacy preservation has become a prerequisite for modern applications in the cloud, social media, Internet of things (IoT), and E- healthcare systems. In general, health and medical data contain images and medical information about the patients and such personal data should be kept confidential in order to maintain the patients’ privacy. Due to limitations in digital data properties, traditional encryption schemes over textual and structural one-dimension data cannot be applied directly to e-health data. In addition, when personal data are sent over the open channels, patients may lose privacy of data contents. Hence, a secure lightweight keyframe extraction method is highly required to ensure timely, correct, and privacy-preserving e-health services. Besides this, it is inherently difficult to achieve a satisfied level of security in a cost-effective way while considering the constraints of real-time e-health applications. In this paper, we propose a privacy preserving chaos-based encryption cryptosystem for patients’ privacy protection. The proposed cryptosystem can protect patient’s images from a compromised broker. In particular, we propose a fast probabilistic cryptosystem to secure medical keyframes that are extracted from wireless capsule endoscopy procedure using a prioritization method. The encrypted images produced by our cryptosystem exhibits randomness behavior, which guarantee computational efficiency as well as a highest level of security for the keyframes against various attacks. Furthermore, it processes the medical data without leaking any information, thus preserving patient’s privacy by allowing only authorized users for decryption. The experimental results and security analysis from different perspectives verify the excellent performance of our encryption cryptosystem compared to other recent encryption schemes.

隐私保护已成为云，社交媒体，物联网（IoT）和电子医疗系统中现代应用程序的先决条件。通常，健康和医学数据包含有关患者的图像和医学信息，因此应对此类个人数据保密，以维护患者的隐私。由于数字数据属性的限制，基于文本和结构一维数据的传统加密方案无法直接应用于电子医疗数据。另外，当通过公开渠道发送个人数据时，患者可能会丢失数据内容的隐私。因此，迫切需要一种安全的轻量级关键帧提取方法，以确保及时，正确和保护隐私的电子医疗服务。除此之外，在考虑实时电子医疗应用程序的限制的同时，很难以经济有效的方式实现令人满意的安全级别。在本文中，我们提出了一种基于隐私保护的混沌加密密码系统，以保护患者的隐私。所提出的密码系统可以保护患者的图像免遭受害经纪人的侵害。特别是，我们提出了一种快速概率密码系统，用于保护使用优先级排序方法从无线胶囊内窥镜检查过程中提取的医疗关键帧。由我们的密码系统生成的加密图像具有随机性，可以保证计算效率以及针对各种攻击的关键帧的最高安全性。此外，它在不泄漏任何信息的情况下处理医疗数据，因此，仅允许授权用户进行解密，从而可以保护患者的隐私。与其他最近的加密方案相比，从不同角度进行的实验结果和安全性分析证明了我们的加密密码系统的出色性能。