Iterative modular multiplication algorithmwithout magnitude comparison
Che Wun Chiou, Ted C. Yang · Electronics Letters · 1994
A fast iterative modular multiplication algorithm is proposed for modular exponentiation with a large modulus, such as the RSA cryptosystem. The limit on partial products is raised to become less than 2n instead of modulus N with n-bit length. The naturally generated carry signifies when the computed partial product is greater than or equal to 2n, and a subtraction is subsequently performed. No magnitude comparisons are required.