Hidden data in Access - advanced stuff folks (maybe)

[MattGaff]

I am looking for a way to have a table (or similar) in an access database that can be queried/read from but not seen in its entirity from any users.

For example, say I wanted a table that had 2 fields - UserName and Password.
There are 20 users in this table and each had a unique password to access another applicaton (or even a website).

A Windows user JBloggs is logged onto the network and runs the database where there is a button on a form called Get Password. When he clicks this, a piece of code is run to get his username from the windows logon session, passes it to the hidden table (or collection) and returns his password.

This is all hypothetical at the moment and was just wondering what methods ways I should use to explore this.
For example, is it possible to create a class library (dll) in Visual Studio with all the table values hard coded in and this dll then referenced from Access. By the Way I have to use Access so I may be limited in what I can achieve.

I look forward to any suggestions.

[NeoPa]

Have you considered encrypting the data stored such that, although it is visible to all, it is interpretable by none?

[MattGaff]

I have considered encryption but wouldn't know how. Am I able to encrypt a table in access and still use it?

[NeoPa]

As long as every access of the data used a function call to decrypt it, Yes.

[MattGaff]

OK sounds good to me.
A couple of things;
i). you know of any tutorials/links that explain the process on how to encrypt a table and decrypt the data using a function?

ii). Would a savvy user be able to see the functions being used to decrypt the table and and write some code to populate a temp table by using the same decrypting code (basically what I am getting at is, is it watertight on the security front)?

[NeoPa]

OK sounds good to me.
A couple of things;
i). you know of any tutorials/links that explain the process on how to encrypt a table and decrypt the data using a function?

Not really I'm afraid. I did find some interesting links by googling "encrypt data routine", but I'll let you see what you can from there.

Remember that most encryption routines need a key which is available to both encrypt and decrypt the data. Keeping this hidden from a determined explorer is a separate problem.

ii). Would a savvy user be able to see the functions being used to decrypt the table and and write some code to populate a temp table by using the same decrypting code (basically what I am getting at is, is it watertight on the security front)?

No. Not (watertight) as far as I can see. I simply use an algorithm which converts the data. It uses no key, and is therefore very weak as far as security goes. It relies on the explorer being baffled and confused. With my target audience that is adequate.

I suppose if you implemented one of the stronger routines and protected the source of your project, you may be able to get a watertight effect.