The goal of this project is to investigate several types of cryptographic protocols that are unconditionally secure, i.e., their security does not require any computational assumptions. Examples of topics to be studied include construction of efficient authentication codes, robust secret sharing schemes, key distribution schemes and broadcast encryption schemes. All of these topics are of fundamental importance in cryptography in providing for confidentiality and/or integrity of information. As the Internet becomes increasingly important in everyday life, security of the information it contains is a critical factor. Hence, methods of providing information security are of great practical importance. Unconditionally secure protocols are very desirable precisely because their security can be rigorously proved and quantified. The main mathematical tools used are combinatorial in nature; error-correcting codes and combinatoral designs play an essential role. Other mathematical techniques come into play in an important way, including information theory and number theory. The two main objectives are to construct new, practical, efficient schemes, and to evaluate them in terms of the amount of secret information that needs to be exchanged and the computational complexity of the actual algorithms that implement them. Thus there is a whole spectrum of activity to be carried out, from initially providing a mathematical solution to the actual implementation of an algorithm.