Differential Fault Attacks on Lightweight Cipher LBlock

Abstract

Lightweight block cipher is usually used in "Internet of Thing" to protect confidentiality as well as to authentication. LBlock is a lightweight block cipher designed for tiny computing devices, such as RFID tags and sensor network nodes. The cipher algorithm iterates a Feistel structure with SP type round function by 32 rounds. Its block size is 64 bits and key size is 80 bits. The designers show that LBlock is resistant against most classical attacks, such as differential and linear cryptanalysis. This paper proposed differential fault analysis on LBlock based on different depth of fault model, the theoretical analysis demonstrates that LBlock is vulnerable to deep differential fault attack due to its Feistel structure and diffusion layer. By injecting faults in the 27 th round to the 29 th round, a differential fault analysis on LBlock based on a nibbleoriented random fault model is presented. The experiment shows that 4.3 faults on average could recover a round key. For reveal the whole key information, 13.3 faults on average are needed. This indicates that cryptographic devices supporting LBlock should be carefully protected.

The differential fault analysis on block cipher FeW

“…Therefore, considering the DFA on key schedule of block cipher is also necessary. In fact, many important works just discussed this for many famous block ciphers, like AES (Takahashi and Fukunaga 2007), ITUbee (Fu et al 2017), LBlock (Wei et al 2018), KLEIN (Gong et al 2011) et al Generally speaking, the induced faults can affect the current and subsequent round subkeys, which will further change the encryption states. Hence, the study of DFA on key schedule becomes more complicated than that of encryption state.…”

Preface

“…In the seventh paper, Wei et al [7], investigate the lightweight block cipher, which is useful in Internet of Things to protect confidentiality as well as to authentication. The authors consider the LBlock -a lightweight block cipher designed for tiny computing devices, such as RFID tags and sensor network node-and is shown resistant against most classical attacks, such as differential and linear cryptanalysis.…”