In this paper, we propose a secure electronic medical record (EMR) service system, named the ECC-based Secure EMR Transmission System (ESEMRT for short) which employs a cloud database, an elliptic curve cryptography (ECC) integration unit, a smart card, and portable devices to provide users with a secure environment for EMR transmission. The ECC integration unit, which integrates a 256-bit ECC chip, wireless transceiver, smart card reader, and USB interface for fast computing and reducing the communication load of a portable device, can securely protect the EMRs when these EMRs are delivered between the cloud database and the portable device so as to enhance their transmission security and the patient care quality. Besides, the data leakage prevention scheme is also implemented in the ESEMRT to avoid illegal duplication. Our simulation shows that the proposed system can provide a higher security level and reduce portable devices' hardware resource requirements.

File encryption is an effective way for an enterprise to prevent its data from being lost. However, the data may still be deliberately or inadvertently leaked out by the insiders or customers. When the sensitive data are leaked, it often results in huge monetary damages and credit loss. In this paper, we propose a novel group file encryption/decryption method, named the Group File Encryption Method using Dynamic System Environment Key (GEMS for short), which provides users with autocrypt, authentication, authorization, and auditing security schemes by utilizing a group key and a system environment key. In the GEMS, the important parameters are hidden and stored in different devices to avoid them from being cracked easily. Besides, it can resist known-key and eavesdropping attacks to achieve a very high security level, which is practically useful in securing an enterprise's and a government's private data.