me
   the problems of 2-lag generators using +,- or xor, I
   have developed the 4-lag generator LFIB4 using
   addition: x(n)=x(n-256)+x(n-179)+x(n-119)+x(n-55)
   mod 2^32. Its period is 2^31*(2^256-1), about 2^287,
   and it seems to pass all tests---in particular,
   those of the kind for which 2-lag generators using
   +,-,xor seem to fail. For even more confidence in
   its suitability, LFIB4 can be combined with KISS,
   with a resulting period of about 2^410: just use
   (KISS+LFIB4) in any C expres