>I have a VFP 7 application with about 60 tables and 10,000 data fields. About 30 of the fields in 5 different tables are unique patient identifiers and must be encrypted. Should I encrypt just those fields or the entire tables?
>I have been using CAPICOM and its 3DES algorithm which I understand is very secure, and it works fine, but a field such as patient name which was a 30 character field must now be a 250 character field to allow for the longer encrypted string. Dates are an even bigger problem, as they can no longer be stored in date fields, but must be stored in character fields as well. What is the best solution?
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>Thanks very much!
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>(Sorry, this is the first question I've asked in a forum like this and I don't yet have a brilliant quote to end with...)

Hi David,
we stroke the same problem when we developed application for Address Data Management. It is nice to encrypt all the data and to open them in memory, but encryption and decryption takes time. We make our own CryptToAPI.DLL on the base of explained by Al in other answer for VFP applications.
In reality from 52 tables we encrypt five tables. And not all five tables, but only meaningful field in it. The size is almost the same in regular variant and with encrypted data.