Common shared keys, which can be used for encryption/decryption, authentication and various other security primitives, plays a fundamental role in securing modern digital systems. Due to such significant importance, there has been a tremendous amount of work on the design of key generation/distribution schemes. Despite of these efforts, significant challenges, such as scalability and availability, remain to be fully addressed. This project investigates information theoretic approaches for secret key generation with focuses on fundamental and challenging issues under more realistic models.