c1 c2 c3=md5(c1) 109168 41d1029d64a6f29bb7a0 d1c8582f3e741d1029d64a6f29bb7a00 146270 1a2a15a96d93717480a7 54d4ddaa30b1a2a15a96d93717480a7a As you see,c2 is part of c3,c2=substr(c3,11,20) and c3 is obviously the md5 result of c1 ,c3=md5(c1) now I want to know how do they encrpt c2 to get c1? is it possible?