The report discusses technical ways to implement digital signature , introduces several representative signature schemes and specifies n - r - q new scheme . in software design , the expression of large integer is defined by a new method based on dsp and large integer operation algorithms are designed according to that . after completing the signature program in assembler by special repertoire of dsp ( tms320c50 ) , we run it on the platform of software simulator and give out the results 针对n - r - qnew数字签名方案,在软件设计中,基于dsp对大整数的表示重新进行了的描述,相应设计了大整数的基本运算算法,用dsp ( tms320c50 )的专用指令系统完成了数字签名软件的汇编程序设计,并在软件仿真平台上对其进行了仿真,通过仿真结果阐述了用dsp实现数字签名的可行性。