I am currently trying to understand and implement the design of post quantum algorithm signature algorithm Dilithium. I have read the document several times and they have just used uniform random sampling for s1 and s2 and they have not provided any algorithm regarding its calculation. Viewing the reference code, doesn't help because I am still unable to understand why have they:
- used 205 for multiplication
- right shift by 10
- multiplication by 5
- and subtraction from t0.
If this is some known algorithm, then just providing the name of the algorithm is good enough otherwise any help regarding this would be very helpful for my research. The code snippet is also attached as reference.