ELiF : An Extremely Lightweight & Flexible Block Cipher Family and Its Experimental Security

In this paper, we analyzed an extreme case of lightweight block cipher design in terms of security and efficiency. To do this, we proposed ELiF block cipher family which has one of the smallest hardware area in a fully serial design. We also defined ELiF to be flexible and scalable so that it can be implemented for real life applications with different scenarios such as fixed key implementations. We also gave hardware implementation results for different implementation settings to show its efficiency and flexibility. Because of its flexible implementation properties, ELiF family of ciphers are suitable for systems with asymmetric computation powers such as RFID reader and tags. We made theoretical and experimental analysis for various block sizes. Using the results for small block lengths, we estimated minimum number of rounds that the cipher becomes secure depending on the block size.