No 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.

No abstract

Significant progress in the development of lightweight symmetric cryptographic primitives has been made in recent years. Security of ciphers against current cryptanalysis methods should be carefully evaluated. Integral attack is one of the most effective attacks against block ciphers. However, traditional integral attack based on byte or word is not available for a bit-oriented cipher. Bit-pattern based integral attack technique, introduced by Z'aba et al. addresses this issue to some extent. In this paper, bit-pattern based integral attack is applied to ICEBERG—a lightweight block cipher efficient in reconfigurable hard-ware. By tracing the propagation of the plaintext structure at bit-level, the balance property is obtained and then key guesses are verified. The result shows that 3, 4 and 5 rounds ICEBERG are not immune to this attack. All attacks presented in this paper manage to recover the full subkeys of the final round.