RSA的实现(matlab加密解密)

clc

clear

disp('产生密钥对:')

p=input('输入第一个大素数：p=');                                     

q=input('输入第二个大素数：q=');

n=p*q

fain=(p-1)*(q-1)

e=floor(unifrnd(0,fain,1,1))                  

while(gcd(e,fain)~=1)|(e<2);

 e=floor(unifrnd(0,fain,1,1))

end

%模n求逆函数

n1=fain;n2=e;b1=0;b2=1;

for i=1:1000

        q1=floor(n1/n2);

        r=n1-q1*n2;

       if r~=0

           n1=n2;

           n2=r;

           t=b2;

           b2=b1-q1*b2;

           b1=t;

       else

         break

       end

end

if n2~=1

  warning('所求的模逆不存在') ;

end

if n2==1

  d=mod(b2,fain)

  fid=input('输入待加密的明文：','s');

f=abs(fid);

for i=1:length(f)  

a=f(i);b=e;c=1;

for j=1:1000

if b==0

        dashuchenmi=c;

end

if mod(b,2)~=0

         b=b-1;

         c=mod(c*a,n);

else

       b=b/2;

       a=mod(a*a,n);

end

end

  dashuchenmi=c;

  miwen(i)=setstr(dashuchenmi);

end

for i=1:length(f)

a2=miwen(i);b2=d;c2=1;

for j=1:1000

if b2==0

  dashuchenmi2=c2;

end

if mod(b2,2)~=0

       b2=b2-1;

       c2=mod(c2*a2,n);

else

       b2=b2/2;

       a2=mod(a2*a2,n);

end

end

       dashuchenmi2=c2;

       mingwen(i)=setstr(dashuchenmi2);

end

end

disp('对所输入的明文进行加密后的密文：')

miwen

disp('经过解密后恢复出的明文：')

mingwen