基于FPGA的DDS型数字信号发生器设计

Analysis and improvement of proxy blind signature scheme

数字信号发生器是集成电路设计及调试过程中经常用到的工具,基于FPGA设计了一种DDS型数字信号发生器,可产生正弦波、方波、三角波和锯齿波这四种信号,并具有频率可调功能。

Through the security analysis of the proxy blind signature scheme which is proposed by Liu et al., it shows that security flaws exist in the scheme： a dishonest original signer can forge the proxy signing key, that is to say it doesn＇ t satisfy strong unforgeability; the proxy signer can make a linkage between the signature on original message and the signature on corresponding blind message, that is to say the scheme is linkable. An improved scheme is pro- posed to overcome these security problems. By modifying the equation of the delegate authorization and the process of blind signature, the new scheme can resist the original signer＇s forgery attacks, and also has tmlinkability.