i am going to be saving data with DPAPI encryption. i am not sure whether i should just have one big file with all the data or should i break up the data into separate files, where every file is its own record. i suspect the entire dataset would be less than 10mb, so i am not sure whether it's worth it to break it down into about a few hundred separate files or should i just keep it one file?
will it take a long time to decrypt 10mb of data?
If you can never think of the hardware your app is going to run on, make it scaleable. It can then run from 10 parallel floppy drives if it's too slow reading from 1.
If your scope is limited to high-perfo computers, and the file size is not likely to rise within the coming next 10 years, put it in 1 file.
For 10 megabytes, I wouldn't worry about splitting it up. The cost of encrypting/decrypting a given volume of data will be pretty much the same, whether it's one big file or a group of small files. If you needed the ability to selectively decrypt individual records, as opposed to all at once, splitting the file might be useful.