To construct BDH (Bilinear Diffie-Hellman) parameter generator in key evolving schemes, the security of BDH problem was researched.The origin of BDH problem was reviewed. Then based on the admissible bilinear map,the decisional BDH problem, computational BDH problem and some variants were analyzed, respectively. As a result, some useful corollaries about BDH security were obtained. Finally, BDH parameter generators using Weil pairing and Tate pairing on supersingular elliptic curves were constructed. The generators could be widely applied to identity based cryptography.