using encyption from a frontend e.g. VB

Loaded Questions. 1st What database are you planning on using? MS Access can encrypt a database with just an option. Other than that there are all kind of encryption routines that you could use. 2nd, How to perform a database backup depends on what database you're using and if backups have to be performed when users are in it or you have it exclusive.

As for me, I'd prefer to write my own encryption and decryption routines. If you are using VB6, you can accomplish this using a sub or a function.. functions would be best as it returns the encrypted or decrypted values.

But to do this, design a good encryption algorithm that cannot be figured out easily.

Database backup depends on which database you are using. The simplest way would be to copy the database files to a different location, like a secondary hard drive or USB drive. You can add in zipping facilities to decrease the size. Good luck!