encrypt data

  • Thread starter Thread starter nerea
  • Start date Start date
N

nerea

I need to encrypt some fields in the database.
How can I do it?
I was thinking about encrypting the data in vba code and
insert it in the table each time it's modified.
Sb know which are the instructions to do it?
Thanks

Nerea
 
Hi,
Here is a simple encrypt/decrypt routine. The 'key' is 5656 but you can change that to anything
you like:

Public Function Decrypt(strIn As String) As String
Dim strChr As String
Dim i As Integer
Dim j As Integer

j = 1

For i = 1 To Len(strIn) / 4
strChr = strChr & Chr(CLng(Mid(strIn, j, 4)) Xor 5656)
j = j + 4
Next i
Decrypt = strChr
End Function

Public Function Encrypt(strIn As String) As String
Dim strChr As String
Dim i As Integer

For i = 1 To Len(strIn)
strChr = strChr & CStr(Asc(Mid(strIn, i, 1)) Xor 5656)
Next i
Encrypt = strChr
End Function
 
Ouch! I feel a known plaintext attack coming on ...

If anyone knows a single example of original text, & the corresponding
encrypted text, they can immediately decrypt every other encrypted text. I
feel that we should point this out, when recommending XOR methods. What if
these posters are planning on encrypting credid card numbers (or somesuch)?

Cheers,
TC
 
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