I need a tool for file integrity checking

Specification:

1. Tool creates dated checksums of all files. This database is stored in memory during operation. After done, results are written to a file in tool folder, root of the drive or in NTFS alternate streams (without affecting file dates). EDIT: Also - Automatic copy of this database to the tools own folder and compare against that before reading checksums, to ensure the DB itself isn't corrupt.

2. When user runs tool to verify checksums, it doesn't verify those files which have their modified date after the checksum creation date. At same time, tool creates new dated checksums for these files.

So this tool is not meant to detect corruption in frequently modified files, but detect corruption of rarely accessed files, when it is convenient.

Such tool sounds so simple that I suppose it already exists? I'm not in the coding mood right now but maybe I'll get around to it if no one beats me to it, too busy modding Skyrim and other fun stuff.

I'd prefer a simple C# command line tool but open to other tools and ideas if they sound like they fit this "when convenient, verify checksums" plan.

Forgot one.

3. It should have allowance in design to allow files to be copied or moved to another partition or directory and still verify against the checksum made BEFORE the move.

I'm not sure how this would be handled in the "root database" scenario. There's few ways but would likely increase complexity of the program or add requirements for the user.

Does NTFS have unique ID for a file that stays same when the file is moved to different drive or different directory in same drive? It may be necessary to use the alternate streams ...

EDIT:

Well I read there's no suitable file UID's, the alternate streams may be the only suitable solution if (3.) is required, but they may have some gotchas that aren't yet known to me. I don't like the idea of creating one for each file in every drive either.

Actually I remember now. I found some russian Low Density Parity Check (LDPC) tools meant for creating parity of files and repairing them later that might also be suitable but I haven't had time to really look into them. Not big fan of the parity files visible all over the place though as I use "Show hidden files" always because Windows hides some files and folders that I need to use all the time.

How about using something like aerofs and grabbing the hashes from its sqlite database?

-Josh

A free TB size cloud backup? I couldn't find much on what/when is the part where someone is going to pay for it. Backups ain't the issue here though. It's figuring out when either the backup or my local copy integrity fails. I'm mostly interested in the local copy integrity though.

I already have a solution in place I developed years ago but it's more complicated, fragile and too much hassle. I like the specified solution, even though it has some limitations it seems good on paper. I'm just wondering whether I have missed any obvious flaws.