what is the matlab code for follwing equation

t=s^e(mod n)
u=m*m
c=(g^t)*r^m mod u

[rjnt Kaur]

i am working on cryptography so need this code for cryptography

Answer 1

[Walter Roberson]

t = mod(s^e, n);
u = m*m;
c = mod((g^t) * r^m, u);

However! It is possible that the values you are working with, such as s^e, are going to (often) be too large to fit in 53 bits. If that is the case, then there are various number theory approaches that can be used to accurately calculate the mod. The details can depend upon whether s and n are mutually prime.

If you are working with cryptography or with prime numbers or with large numbers or with Galois Fields, or with CRCs, or with error-correcting polynomials, then you should probably not be using the straight-forward method I show above.

[Walter Roberson]

See http://www.mathworks.com/help/symbolic/mupad_ref/powermod.html

[Walter Roberson]

http://www.mathworks.com/matlabcentral/answers/57768#answer_69971