How to do: Multiple Row Allocation within a for loop for a Variable in GF (2^m)

Question

lalonded 2015-11-12

0
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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/254546-how-to-do-multiple-row-allocation-within-a-for-loop-for-a-variable-in-gf-2-m

评论： RESHMA 2017-1-17

Hello all,

Recently, I started working on a ECC implementation in Matlab to model the ECDH (elliptic curve diffie-hellman key exchange) algorithm. Everything was going great until I wanted to allocate each point on the curve starting from my base point i.e. P1 (base), P2, P3, P4, ... etc. I thought that a simple for loop would do the trick like this...

    m = 9;
    x1=6;
    y1=298;
    % Input GF allocation for EC in GF(2^m) --> first point (Base point)
x0 = gf(x1,m);
y0 = gf(y1,m);
 A = [x0,y0]           % 'A' is to show that without a for loop, the allocation works as expected and shown in the output
 for i = 1 : 2         % Test loop, in my code I have while 1 and a break to work with the rest of my code accordingly
    if i == 1
        B(i) = [x0,y0] % <------------'B(i)' won't allocate correctly
    end
 end

But to my surprise I was stuck with the following error... I don't know if this is a problem with the internal Matlab function gf() or if there is a specific way to do this allocation. I cannot allocate each point by brute-force because there will be MANY points, therefore I need to use a loop.

I want to thank you in advance for your time, explanation, and efforts in helping me tackle this problem I am facing; have a fantastic day!

- Dylan R.