In the bachelor thesis Lightweight cryptography I describe the basics of light cryptography, analyze and compare selected lightweight symmetric ciphers. Lightweight is about trade-off between low-cost, security and performace. There are many lightweight ciphers designes, therefore I chose nad explored some of those from the point of view of their features, hardware implementation, performance and security. Analyzed ciphers are in total of fifteen and include E0, A5/1, GRAIN, Trivium, LED, SKINNY, RECTANGLE, SPARX, mCrypton, PRESENT, SIMON and SPECK, XTEA, SEA, LBlock and CLEFIA. I have come to the conclusion that the stream cipher GRAIN is very fast and safe. Block ciphers LED and SKINNY are well secured and SIMON and PRESENT hardware-efficient. With the increased use of constrained devices, it is also necessary to keep up with security, so lightweight cryptography could have a great future ahead
