Encryption problem

[rgw]

Did some work last year converting credit card data into an encrypted field using the native VFP _crypt.vcx.

Got sidetracked onto something else and have only just picked up the test data again. Have a file with thousands of cards and I've found that although the vast majority encrypt/decrtypt as expected maybe 5% will not decrypt--just get a blank. Not good.

Using the same key for both sides of the process. Must be doing something very dumb here and would appreciate any thoughts.

Get the same problem on an XP and a Vista machine. Using VFP9

many thanks
rgw

 

[Mike Gagnon]

I think there is an issue with that class.
You may want to try this instead:

http://www.sweetpotatosoftware.com/SPSBlog/2007/08/06/VFPEncryptionUpdate.aspx

Mike Gagnon

If you want to get the best response to a question, please check out FAQ184-2483 first.
ReFox XI (www.mcrgsoftware.com)

 

[rgw]

Mike

Many thanks. As very much of a non-technical type find it a bit frustrtating when the simple stuff doesn't work. I assume the problem is that there is a problem with doing the encryption in blocks--the 'streaming' code seems to work fine but it looks rather weak when you look at the encrypted results-especially on credit card data which has a very limited number of variables.

My problem is that I have no idea of how to work with the extraced fll. Can youb point me in a direction how to get started with fll's and Craig Boyd's much praised fll in particular.

Appreciate any help you can give me

Many thanks
rgw

 

[rgw]

Shouldn't have been lazy execting t to be harder than anticipated.

Many thanks Sweet Potato.

rgw

 

[Mike Gagnon]

You mean code samples?

http://www.sweetpotatosoftware.com/SPSBlog/PermaLink,guid,b1281831-9655-47f6-9366-be849b9f4598.aspx

http://www.sweetpotatosoftware.com/SPSBlog/PermaLink,guid,23a74c5d-5173-420e-af23-22494d95a54c.aspx

http://www.sweetpotatosoftware.com/SPSBlog/PermaLink,guid,5f4231f7-abc5-4649-a74d-6779f0bce659.aspx

http://www.sweetpotatosoftware.com/SPSBlog/PermaLink,guid,99cd23d6-82b6-4a17-8385-651b3cb37e05.aspx

Mike Gagnon

If you want to get the best response to a question, please check out FAQ184-2483 first.
ReFox XI (www.mcrgsoftware.com)

 

[rgw]

Mike

thanks for the links. My triumph was short lived: i'm working exclusively on credit cards and get 99% of them to encrypt/decrypt perfectly using the more secure methods shown in Craig Boyd's update of August 6, 2007. I think it's a problem with the string length.

rgw

 

[rgw]

Mike

Believe I solved it--had a problem with 22 of 15,000 cards. If the encrypted value had a space at the end I seemed to run into problems--probably a bit too much of the alltrim. I didn't use the chr(0) padding suggested by Craig but rather stored the length of the original encrypted value and brought that substr back from the encrypted field when I was decrypting. So far so good but appreciate your help.

rgw