Radio Frequency Identification (RFID) systems are rapidly becoming popular in a variety of applications such as supply chain management, storage management and healthcare. Such a system consists of a tag with a unique identifier, a tag reader and a backend server. Due to the system's limited computational resources, it can be subject to various types of attacks. This can exacerbate when the reader itself is mobile. The objective of this thesis is to propose a mutual authentication scheme for mobile RFID systems. Our proposed scheme uses a shared encryption key generated and updated by the mobile reader to authenticate the system entities. The encryption keys are updated at the end of each authentication session. Experimental results show that the proposed scheme meets the security and privacy goals, and resists known attacks on mobile RFID systems

This diploma thesis deals with the technology of production of ultralight concretes using direct lighten cementing compound and at the same time indirect lighten using lightweight aggregate. Further work deals with the choice of suitable raw materials for these concretes. The practical part consists of a proposal of several different recipes, experimental verification and by comparing their properties in a fresh or hardened state.