Answer:
I am not sure there is such a thing as a portable safe, but for identification purposes if what you are referring to is one of the keyed "fire safes" found in department stores there are 2 options take it to a locksmith and have it picked open so that you can continue to use it if you find the keys in future, ore if it is just as easy and cheap to replace it and you only want it open try a large flat screw driver! It should pop open extremely easily.