Just reverse the operation
```py#!/usr/bin/env pythonfrom pybitrot import ror8, rol8
def decrypt(buf):    out = bytearray()    for x in buf:        a = rol8(x, 8) ^ 0x16        b = ror8(a, 4)        out.append(b)    return out
def main():    buf = bytearray("\x11\x80\x20\xe0\x22\x53\x72\xa1\x01\x41\x55\x20\xa0\xc0\x25\xe3\x35\x40\x55\x30\x85\x55\x70\x20\xc1")    rs = decrypt(buf)    print(bytes(rs))
if __name__ == '__main__':    main()```