Just save as encrypted float and read back as encrypted float, you might get some variation but its float point inaccuracy...
the other way is to make a memblock four bytes wide, and use dbWriteMemblockFloat(ID,0,Value)
read into an integer
MyInt = dbMemblock(ID,0);
MyInt = SomeWeirdEncrypter(MyInt);
You can save it here, or force it back to float by putting it back in to memblock then reading it back into a float variable then save it! (OUCH) Lot of work BUT it describes a technique you should learn.
TYPE CASTING!!!!!
Type Casting lets you FORCE a value in a variable to be handled like a different data type. However your first curve ball is that when you type cast a INTEGER as a float or vice versa, its not ACTUALLY type casted, its converted for you... (or against you depending on your point of view LOL.)
Everything is REALLY a BYTE or a string of them - so type casting a FLOAT as a four byte array, and acecessing the 0,1,2,3 elements would allow you to tweak individual bytes. If you don't lose any bits (via lossful encryption versus good lossless scrambling) THEN you can get EVERYTHING BACK the same way in reverse.
Better still, you could write the data all to a memblock, and save the memblock in one fell swoop - encrpyed, binary, and ...well MESSED up for the casual Game MODDER or Media Pirate