Encryption Algoritm

[CJBIRKIN]

Hi,

I've written an encryption algorithm that requries the multiplication of 2 large (32+ character) integers.

say IntA and IntB


My problem is i need to retain the indivdual characters that are created by the muliplication of IntA and IntB, the programme uses the 1.0^X notation as soon as i do the multplication.

If i try to do the division of the mulitplication product of IntA and IntB (IntC) i do not get back the original number i.e. IntC/IntA ~ IntB.

Is there a way round this?


Cheers

Chris

 

[dcx693]

I think the basic answer is that Access cannot store more than 15 digits of precision (check out the specifications of the double and single data types). It just wasn't designed for it. Past 15 digits, it will either round or truncate the number and assign an exponent to it.

What can you do? If you need to use Access, I'd say look for an alternative encryption solution. I found this AES Encyption sample on the 'net, but haven't toyed with it too much: http://www.rogersaccesslibrary.com/Otherdownload.asp?SampleName='AES Encryption.zip'

 

[bretto]

You could use something like the add in found here;

http://precisioncalc.com/

It's designed for excel but works fine in access via vba (results are returned as strings) and gives you massive precision. They do a free one which has a popup and various paid for versions which have varying levels of precision up to something silly. I think the free one works with numbers with a precision of up to 150.

 

[CJBIRKIN]

Hi,

DCX & Bretto;

I've found away of doing RSA encryption using VBA, the only problem is the limit to the 2 primary numbers used to create the Public and Private key pairs. Bretto, thanks v much for the site i'm going to have a play with it. I'll post back if i can get this to work, should provide strong encryption for sensitive fields.

Cheers

Chris