I want to encrypt a message such as 'HELO1234 and then decrypt to get the original one.I have written RSA code in matlab which is not working correctly.
PARAMETER CALCULATION
temp=1;
range=1:10;
k=isprime(range)
prime_mat=range(find(k))
p=randsample(prime_mat,1);
q=randsample(prime_mat,1);
if(p~=q)
n=p*q;
phi_n=(p-1)*(q-1);
u=1:phi_n -1;
end
while temp
enckey=randsample(u,1);
deckey=randsample(u,1);
if(enckey~=deckey)
if(gcd(enckey,phi_n)~=1 ...
&& gcd(deckey,phi_n)~=1 ...
&&gcd(enckey*deckey,phi_n)~=1)
temp=1;
else
temp=0;
end
end
end
ENCRYPTION PROCESS
char t= 'hello123';
t=uint8(t);
len=length(t)
pow=[];
cipher_text=[];
for i=1:len
pow=[pow;t(i).^(enckey)]; %each element of the pt matrix(plain text) is raised to the power of encryption key(enc_key) and stored in pow matrix(power matrix)
cipher_text=[cipher_text;mod(pow(i),n)];% cipher text is calculate
d
OUTPUT OF encryption process
k =
0 1 1 0 1 0 1 0 0 0
prime_mat =
2 3 5 7
p =
7
q =
2
n =
14
enckey =
5
deckey =
1
phi_n =
6
len =
28
cipher_text =
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
DECRYPTION PROCESS
plain_text=[];
pow1=[];
len1=length(cipher_text);
for i=1:len
pow1=[pow1;cipher_text(i).^(deckey)]
plain_text=[plain_text;mod(pow1(i),n)]
uint8(plain_text);