poster
2019-11-26, 05:22
<p>I am simulating a mini AES encryption/decryption algorithm using MATLAB. For this I need to multiply two 4-bit numbers while treating them as polynomials. It goes though some stages, that are, converting to polynomials, multiply the two polynomials, polynomial reduction to lower power if needed using a predefined irreducible polynomial. Then converting back to 4-bit format.</p>
<p>For instance, multiplying 1011⊗ 0111 is analogous to x3+x+1 ⊗ x2+x+1 The ans is x5+x4+1 has of a power of 5 then you need to reduce it by dividing on the predefined polynomial x4+x+1. The answer will be x2 that is 0100. </p>
<p>I know that there are some functions in MATLAB doing polynomial multiplications but they are kind of general and need some specific function or method to do this.</p>
<p>Many thanks in advance!</p>
More answer... (https://stackoverflow.com/questions/59040092/how-to-do-multiplication-for-two-4-bit-numbers-treating-them-as-polynomials-in-m)
<p>For instance, multiplying 1011⊗ 0111 is analogous to x3+x+1 ⊗ x2+x+1 The ans is x5+x4+1 has of a power of 5 then you need to reduce it by dividing on the predefined polynomial x4+x+1. The answer will be x2 that is 0100. </p>
<p>I know that there are some functions in MATLAB doing polynomial multiplications but they are kind of general and need some specific function or method to do this.</p>
<p>Many thanks in advance!</p>
More answer... (https://stackoverflow.com/questions/59040092/how-to-do-multiplication-for-two-4-bit-numbers-treating-them-as-polynomials-in-m)