Increment Nonce by any fixed value in loop

I have the nonce value in hex. Let say:

nonce = {'00' '11' '22' '33' '44' '55'};

I need to add any fixed value 'x'(hex) to this value in loop and need to save every new value.

I was doing this like:

nonce = {'00' '11' '22' '33' '44' '55'};

for i=1:5

nonce(i) = nonce + 01;

i = i+1;

end

But I am not acheiving what I need.

[Jan]

Please mention, what you expect as output. Having only not running code does not clarify, what you want to achieve.

Your code contains some bugs:

for i=1:5
    nonce(i) = nonce + 01;
    % Here on the left side there is a scalar cell element, and on
    % the right you try to add 01 (which is the same as 1) to a
    % cell vector.
    
    i = i+1;  % i is iterated by the FOR loop already
              % so do not increase it manually
end

Answer 1

[Alex Mcaulley]

Using a loop:

nonce = {'00' '11' '22' '33' '44' '55'};
x = '01';
for i = 1:numel(nonce)
    nonce{i} = dec2hex(hex2dec(nonce{i}) + hex2dec(x),2);
end

Or using cellfun:

nonce = {'00' '11' '22' '33' '44' '55'};
x = '01';
nonce = cellfun(@(y) dec2hex(hex2dec(y) + hex2dec(x),2),nonce,'uni',0);

[Zeeshan Abbas]

Thank you but it's giving me: nonce = {'01' '12' '23' '34' '45' '56'}

I need it to be: nonce = {'00' '11' '22' '33' '44' '56'}; just need to increament the whole value by 1, not every element. We can increament it from deecimal value as well and then at last convert it into hex. But I need to increment the value 5-times and need to save every value.

The ultimate usage is to use this as a nonce/counter value in CTR mode block cipher to create bit stream.

[Alex Mcaulley]

Well, then an option is:

nonce = {'00' '11' '22' '33' '44' '55'};
x = '01';
a = strcat(nonce{:});
for i = 2:6
    a(i,:) = dec2hex(hex2dec(a(i-1,:)) + hex2dec(x),12);
end

nonce = mat2cell(a,ones(6,1),2*ones(6,1))
nonce =

  6×6 cell array

    '00'    '11'    '22'    '33'    '44'    '55'
    '00'    '11'    '22'    '33'    '44'    '56'
    '00'    '11'    '22'    '33'    '44'    '57'
    '00'    '11'    '22'    '33'    '44'    '58'
    '00'    '11'    '22'    '33'    '44'    '59'
    '00'    '11'    '22'    '33'    '44'    '5A'

At the end of the code, each row of nonce corresponds with the value in each iteration.

[Zeeshan Abbas]

Thank you very much. It's giving what I asked, so I am accepting. Although it don't worked for me in that scenario in which I was seeking this.

Answer 2

[Jan]

nonce = {'00' '11' '22' '33' '44' '55'};
toAdd = hex2dec('01');
for k = 1:5
    nonce{k} = dec2hex(hex2dec(nonce{k}) + toAdd);
end

It might be easier to work with a double vector, if you want to perform calculations. Then hex strings are rather inefficient.