Abstract: This paper presents and realizes a rapid carry adder based on carry forecast between groups to improve the speed of the large numbers adder in some cryptography systems. The large numbers is divided into many groups, the delay of carry-chain is reduced by carry lookahead in group. The group addition operation of different carry state is finished by carry forecast between groups. The addition sun of different carry forecast state is selected as the final result based on the carry state. Performance analysis shows that the computing speed of the carry adder is faster when realizing the 1 024 bit large numbers add operation.

Key words: carry forecast, large numbers adder, carry lookahead, grouping, carry adder

摘要： 为加快密码系统中大数加法的运算速度，提出并实现一种基于组间进位预测的快速进位加法器。将参与加法运算的大数进行分 组，每个分组采用改进的超前进位技术以减少组内进位延时，组间通过进位预测完成不同进位状态下的加法运算，通过每个组产生的进位状态判断最终结果。性能分析表明，该进位加法器实现1 024位大数加法运算的速度较快。

关键词: 进位预测, 大数加法器, 超前进位, 分组, 进位加法器

CLC Number: 

• TP309