Biclique Cryptanalysis On Lightweight Block Ciphers

Due to the rise of Internet of things?IOT?and its applications,wireless communication and embedded systems are developing rapidly.IOT applications have been around the scene in all aspects of daily life,such as public transportation,smart cards and electronic payment.Corresponding running environment to IOT applications are micro computers,embedded devices and battery-driven devices,the data processing ability and storage ability of all these divices are limited,therefore they are called the resource-constrained devices.To ensure the security of encryption and decryption on these devices,the low energy consumption,small chip area,low latency and high efficiency are proposed for the cryptographic algorithms.In this background,the block ciphers have entered the era of light quantization.Lightweight block ciphers have become the focus and hotspot in cryptography.The lightweight block cipher will play an increasingly important role in the security of embedded systems.Choosing a lightweight block cipher on a resource-constrained device must be very cautious and have enough confidence in the security of this cipher.Otherwise,once the lightweight block cipher is put into use,it will cause irreparable damage when serious loopholes and defects are found.Therefore,the security analysis of lightweight block ciphers has very important practical significance in terms of personal information protection,theoretical research and commercial value.Meanwhile,the cryptanalysis of lightweight block ciphers helps to find out the balance between efficiency and security in design process,and also has the guidance for the design and the cryptanalysis of new block ciphers.Biclique cryptanalysis is an effective method for the security analysis of block ciphers.The main idea of Biclique cryptanalysis is to divide the key space into partitions by complete two partite graph structure and use the MITM attack to complete the key recovery attack.This method is an optimized exhaustive attack,which is very effective for the cryptanalysis of lightweight block ciphers also.In this paper,we mainly study the cryptanalysis of lightweight block ciphers using Biclique cryptanalysis.Firstly,we introduce the knowledge about block cipher and lightweight block cipher,and then introduce the related knowledge of Biclique cryptanalysis method in detail.This is the groundwork for the following specific attacks.Secondly,the core research content of this paper is the full round Biclique attack on three lightweight block ciphers,the results are as follows:?1?The full round Biclique cryptanalysis is performed on KLEIN-96.We perform the attack from plaintext direction and construct a 8-dimensionin Biclique structure,and then we complete the full round attack by matching the matching variable in 9th round finally.The time complexity,data complexity and storage complexity of our attack are2^95.16,2³² and⁸2 respectively.?2?We perform full round Biclique cryptanalysis on Midori64.The 4-dimensionin Biclique structure which covers the first 3 rounds of the cipher is constructed from plaintext.Based on the structure,we match the matching variable in10th round,and then complete the full round attack by precomputation and recomputation.The time complexity,data complexity and storage complexity of our attack are2^126.67,2³⁶ and⁴2 respectively.?3?We perform the full round Biclique attack on SKINNY-64-64.Based on the related-key differencial in the1st round,the independent Biclique of 6 rounds and 4 dimensions is constructed.Then we do the partial matching process from forward direction and backward direction respectively to match the matching variable in 18th round,and then we complete the full rounds attack finally.The time complexity,data complexity and storage complexity of our attack are2^63.02,2⁴⁸and⁴2 respectively.In addition,the result of the attack on SKINNY-64-64 is optimized by modifying the matching variables.The time complexity of the attack is reduced to2^62.87.Finally,on the basis of the Biclique cryptanalysis on three lightweight block ciphers,the advantages and disadvantages of Biclique attack cryptanalysis are summarized.In view of the shortcomings of Biclique cryptanalysis,some future research directions and suggestions are given.These suggestions will help to improve the efficiency of Biclique cryptanalysis and broaden the use of this method.