Cryptographic system Diffie-Hellman for key exchange

Theme of this bachelor thesis is cryptographic system Diffie-Hellman for key exchange. Brief description of other asymmetric cryptographic systems is also part of the content of this work. Within topic, cryptographic system Diffie-Hellman, aim of this work is description of this system, it's variants, their concretization, differences and how are they implemented and used in described protocols. Practical part demonstrates application of configuration in one of the described protocols.Aim of this work is to clarify application specifics of cryptographic system Diffie Hellman in different protocols. This work analyses groups of Diffie-Hellman, compares their differences and markings in described protocols and suggests way of division of these groups into a categories. Practical part contains demonstration of usage of cryptographic system Diffie-Hellman in IPSec protocol. First the design of topology where communication took place was made. Then the topology was implemented along with configuration and testing of functionality of configuration.Within the protocols described in this work many ways of configuration of Diffie Hellman system can be used which this work also describes. These ways of configurations were collectively marked using term group. Groups of Diffie-Hellman determines strength of key and they can be divided into three categories based on used method and finite field which they work in. These categories were organized and summarized for protocols described in this work.