Multiply Constant-Weight Codes and the Reliability of Loop Physically   Unclonable Functions
  We introduce the class of multiply constant-weight codes to improve the reliability of certain physically unclonable function (PUF) response. We extend classical coding methods to construct multiply constant-weight codes from known $q$-ary and constant-weight codes. Analogues of Johnson bounds are derived and are shown to be asymptotically tight to a constant factor under certain conditions. We also examine the rates of the multiply constant-weight codes and interestingly, demonstrate that these rates are the same as those of constant-weight codes of suitable parameters. Asymptotic analysis of our code constructions is provided. 
Yeow Meng Chee, Zouha Cherif, Jean-Luc Danger, Sylvain Guilley, Han   Mao Kiah, Jon-Lark Kim, Patrick Sol\'e, Xiande Zhang
cs.IT math.CO math.IT