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ginoplusio on 11/18/08

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# ASP function to encrypt ID (number only)

/ Published in: ASP   These are two function used to encrypt and decrypt the ID you don't want to show (for example the id of the user to be saved in the cookies...)

`Function Encrypt(theNumber)	Dim n, szEnc, t, HiN, LoN, i	n = CDbl((theNumber + 1570) ^ 2 - 7 * (theNumber + 1570) - 450)	If n < 0 Then szEnc = "R" Else szEnc = "J"	n = CStr(abs(n))	For i = 1 To Len(n) step 2	  t = Mid(n, i, 2)	  If Len(t) = 1 Then	   szEnc = szEnc & t	   Exit For	  End If	  HiN = (CInt(t) And 240) / 16	  LoN = CInt(t) And 15	  szEnc = szEnc & Chr(Asc("M") + HiN) & Chr(Asc("C") + LoN)	Next	Encrypt = szEncEnd Function Function Decrypt(theNumber)	On Error Resume Next	Dim e, n, sign, t, HiN, LoN, NewN, i	e = theNumber	If Left(e, 1) = "R" Then sign = -1 Else sign = 1	e = Mid(e, 2)	NewN = ""	For i = 1 To Len(e) step 2	  t = Mid(e, i, 2)	  If Asc(t) >= Asc("0") And Asc(t) <= Asc("9") Then	   NewN = NewN & t	   Exit For	  End If	  HiN = Mid(t, 1, 1)	  LoN = Mid(t, 2, 1)	  HiN = (Asc(HiN) - Asc("M")) * 16	  LoN = Asc(LoN) - Asc("C")	  t = CStr(HiN Or LoN)	  If Len(t) = 1 Then t = "0" & t	  NewN = NewN & t	Next	e = CDbl(NewN) * sign	Decrypt = CLng((7 + sqr(49 - 4 * (-450 - e))) / 2 - 1570)End Function` Subscribe to comments