>>Anyhow, just thought I would ask in case someone who does more "mathy" stuff knows if VFP has some capability I am not aware of.

Helicopter view = encryption needs to reliably obfuscate and de-obfuscate values. For strings, faulty decryption usually is easily detected. For numerics, it could be a big problem if the error is not immediately obvious. Especially where rounding is involved in VFP. E.g. "Albert" decrypting back to "Al$5rCF" is a fairly obvious glitch, but $100.32 decrypting back to $100.30 isn't obvious unless somebody is watching closely.

So for numerics I'd say the immediately obvious ofuscation is adding or subtracting that doesn't risk rounding. Floating point multiplication or any other function that risks rounding, could mess you up.

Ideally the added value differs per record, so it can't be guessed by knowing one value. As an example you could use a derivative of SYS(2017) or SYS(2007) to get a CRC for each record and add that. Example: calculate remainder of a division on CRC of decrypted username. The following code shows unpredictably different numerics: not only is the CRC hugely different for slightly different names, but the % remainder obfuscates futther (and helps avoid numeric overflow situations): also means a hacker would need to decrypt the username, know to use CRC, and know your denominator:

lnPayment=105.54

lcDecryptedname="GOSTICK, Albert"
? "Albert =",m.lnpayment

lnObfuscatedpayment=m.lnPayment+VAL(SYS(2007,m.lcDecryptedName,0,1))%12345
? "Obfuscated=",m.lnObfuscatedpayment

lnUnobfuscatedpayment=lnObfuscatedpayment-VAL(SYS(2007,m.lcDecryptedName,0,1))%12345
? "Unobfuscated=",lnUnobfuscatedpayment

?

lcDecryptedname="GOSTICK, Alberta"
? "Alberta=",m.lnPayment

lnObfuscatedpayment=m.lnPayment+VAL(SYS(2007,m.lcDecryptedName,0,1))%12345
? "Obfuscated=",m.lnObfuscatedpayment

lnUnobfuscatedpayment=lnObfuscatedpayment-VAL(SYS(2007,m.lcDecryptedName,0,1))%12345
? "Unobfuscated=",lnUnobfuscatedpayment

Note that without inside information, this is enough to thwart casual examination and most hackers, but somebody who knows how to hook VFP can deduce all your encryption efforts in minutes. If that's a concern, the latest Refox or Defox or (my favourite) VFP Compiler have only ever been convincingly hacked by 3 people, 2 of whom are authors of 2 of these products. Level of paranoia depends who you need to protect yourself from!