linear feedback shift register in cryptography

These variables private bool _register = null The SHA256Managed class implements IDisposable through inheriting HashAlgorithm so you should enclose its usage in a using block. This will avoid hidden bugs and the code looks better structured. I would like to encourage you to always use them. Public Register ( int length, int feedbackPoints ) : this ( length, feedbackPoints, new byte ), although they might be optional, can lead to hidden and therefor hard to track bugs. Here is my LFSR implementation public class Register The strange thing is in my test the period is exactly half of what expected/declared by the paper (not (2^n)-1 but 2^(n-1)). My implementation accept some parameter so can be adapted to various feedback polynomials (my refernce table)įor the testing pahse i generate as many number as the cycle will allow before a repetiton (i use a byte to my testing purpose).ĮDITED (PROBLEM SOLVED IT WAS DUE A TYPO, QUESTION REPHRASED AT THE END) That did work (I'm guessing it's correct because it stopped).I haven't found any implementation in C# of the LFSR so accordling to Wikipedia i have implment it to myself. I looked at the wikipedia page, and changed the rightmost term from + 1 to + lfsr per the wiki. I did the polynomial in your comment, but it did not work (seemed to loop infinitely). This way seems to assume the lsb left and the msb right, so that we shift everything onto the msb's positon and xor it. I want the polynomial in my comment, which seems to be the one pointed out. I have used uint32_t for all my data types and lfsr is set to start_state when the function is called.

I want to implement a Linear-feedback shift register for the following polynomial x^24 + x^23 + x^22 + x^20 + x^19 + x^18 + x^17 + x^16 + x^15 + x^13 + x^12 + x^8 + x^7 + x^6 + 1, relying on what can be found here with the associated C code:

Linear feedback shift register in cryptography