Modern techniques for decentralized key establishment in symmetric cryptographic systems

Strength of the symmetric cryptographic systems, in addition to the quality of the applied cryptographic algorithm, is based on the quality and secrecy of the used cryptographic key. The generation and distribution of cryptographic keys is a bottleneck in the exploitation of symmetric cryptographic systems in mass network communications. This paper presents two modern concepts for cryptographic key establishing in symmetric cryptographic systems. Both concepts provide solutions for the decentralized establishment of cryptographic keys in symmetric cryptographic systems without the involvement of a trusted third party. Cryptographic keys generated by the systems based on these concepts possess cryptographically good statistical characteristics. From the security point of view, keys generated by different concepts belong to different security classes. Some results of related projects in which the authors participate are highlighted, as well as some open questions in this area.