NTRU note
===

$N = 11$
$p = 3$
$q = 8$

## NTRU
[Spec](https://ntru.org/f/ntru-20190330.pdf)
只需要看 NTRU-HPS

擴展歐幾里得算法(Python)

def ext_euclid(a, b):
    old_s,s=1,0
    old_t,t=0,1
    old_r,r=a,b
    if b == 0:
        return 1, 0, a
    else:
        while(r!=0):
            q=old_r//r
            old_r,r=r,old_r-q*r
            old_s,s=s,old_s-q*s
            old_t,t=t,old_t-q*t
    return old_s, old_t, old_r

此函數得 `a` 模 `b`
$a \equiv old_s\ \ mod\ \ b \\ if \ old_r = 1, \\ else \ not\ exist$

## Xilinx C
[Xilinx Standalone Library Documentation](https://www.xilinx.com/support/documentation/sw_manuals/xilinx2018_2/oslib_rm.pdf)