Buy a media safe ( small one -just larger than a shoebox)and put this inside a fire safe. Even Wal Mart has cheap ones. The best way to buy a firesafe is to go to a used safe store. The prices are usually a fraction of the cost of a new safe. Basement temperatures in a fire are often very low and this is usually the best place for the safe. Be sure to have the safe off of the floor by 6" or so-More if basement flooding an issue. You can also put water sensitive articles in a waterproof container. Very large safes are often very cheap as most people have no use for them. If you ever do a room addition with a basement have a giant safe dropped in just after the floor is poured and before the 1st floor joists are put down. My 7ftH x4'W x 3'D two door safe cost me $1000 including curbside delivery and the cost of a crane to stop by and hoist it into the basement. Best idea I ever had for secure storage.