Today, computer networks are utilized for the sharing of information and resources more than ever before. Data transmitted over any network can exposed to many devious activities. To protect the information flowing through these networks involves the design and implementation of systems that maintain security. The aim of this thesis is to investigate Rank codes for implementing communication security techniques for different application areas. This thesis can be divided into three parts. Each of these parts are summarized below: Wireless sensor networks are increasingly becoming viable solutions to many challenging problems. Security is one of the main issues in some of the application areas of wireless sensor networks such as military and Supervisory Control and Data Acquisition (SCADA) applications. Key distribution is a fundamental prerequisite for secure communication in any network. Due to the inherent resource and computation constraints of sensor nodes, link key establishment among the nodes is non-trivial. Numerous key exchange schemes have been proposed so far but key pre-distribution schemes are perhaps well suited for large scale deployments of resource constrained sensor networks. We have studied different key pre-distribution schemes and proposed a scheme based on the generator matrix of maximum rank codes.