CAJ | 학술논문

该文分析研究了LBlock分组密码算法的不可能差分性质.基于LBlock算法的轮函数结构和部分密钥分别猜测技术,给出了21轮和22轮的LBlock算法的不可能差分分析方法.攻击21轮LBlock算法所需的数据量约为262,计算量约为262次21轮加密;攻击22轮LBlock算法所需的数据量约为262.5,计算量约为263.5次22轮加密.与已有的结果相比较,分析所需的计算量均有明显的降低,是目前不可能差分分析攻击LBlock的最好结果.
해문분석연구료LBlock분조밀마산법적불가능차분성질.기우LBlock산법적륜함수결구화부분밀약분별시측기술,급출료21륜화22륜적LBlock산법적불가능차분분석방법.공격21륜LBlock산법소수적수거량약위262,계산량약위262차21륜가밀;공격22륜LBlock산법소수적수거량약위262.5,계산량약위263.5차22륜가밀.여이유적결과상비교,분석소수적계산량균유명현적강저,시목전불가능차분분석공격LBlock적최호결과.
The impossible differential property of LBlock block cipher is analyzed. Based on the property of the structure of round function and the technology of key-byte guessing, two impossible differential attacks on 21-round and 22-round reduced LBlock are presented. It is shown that the attack on 21-round requires about 262 chosen plaintexts and 262 21-round encryptions, and on 22-round requires about 262.5 chosen plaintexts and 263.5 22-round encryptions. The presented results are the best impossible differential attack on reduced-round LBlock so far.