I was thinking of it in the opposite way - the number 191 hashes into LTL or BJL, which is why the encryption produces two different outputs. The alphabetic value is representing a decimal number, not a decimal representing an alphabetic value.
That example is convertable both ways = I can convert 191 into either LTL or BJL, and either one of those two values can be converted back to 191. Hashing is not always a "theoretically unique" value. I know of hashes that will produce the same hash value from different input values, but those are not typically used in encryption/decryption algorithms, where recovery of the original form is an issue. I've seen them in storage algorithms when I was a student. In the end, I am not an encryption expert but I play one on TV. :-) I was offering the reason I thought it most likely that the encryption algorithm offers up multiple versions of encrypted text from the same data. Matthew Small IT Supervisor Showstopper National Dance Competitions 3660 Old Kings Hwy Murrells Inlet, SC 29576 843-357-1847 http://www.showstopperonline.com -----Original Message----- From: Mosh Teitelbaum [mailto:[EMAIL PROTECTED]] Sent: Wednesday, November 20, 2002 4:52 PM To: CF-Talk Subject: RE: Encryption gurus please read Err... this way would make it near impossible to decode the value. Using your simple example, how would the decryption routine know which value to return when decrypting "191?" Should it return "BJL" or "LTL?" Also, encrypting should not be confused with hashing. Encrypting a value uses a 2-way algorithm so as to allow the encrypted value to be decrypted (i.e., "abc" -> "X%2" -> "abc"). Hashing creates a theoretically unique value that is difficult to near-impossible to "decrypt" (i.e., "abc" -> X%2 -> ???). I have checked out the CustomTags mentioned, but earlier versions of ColdFusion (and, I suspect, these CustomTags) sometimes add junk on to the end of the encryption string (perhaps, to return a fixed length string). So, depending on whatever internal algorithm is used, encrypting "abc" with a key of "123" may randomly produce "xyzpdq123" or "xyzpdq456" or "xyzpdq789". Note how in this (admittedly contrived) example, the first 6 characters are the same... only the last 3 differ from outcome to outcome. In decrypting, the function/CustomTag somehow detects that only the 1st 6 characters are relevant and uses those to decrypt the string back to its original value. -- Mosh Teitelbaum evoch, LLC Tel: (301) 625-9191 Fax: (301) 933-3651 Email: [EMAIL PROTECTED] WWW: http://www.evoch.com/ > -----Original Message----- > From: Matthew Small [mailto:[EMAIL PROTECTED]] > Sent: Wednesday, November 20, 2002 3:49 PM > To: CF-Talk > Subject: RE: Encryption gurus please read > > > I think it's because encrypted values are not evaluated for their own > value, but are rather hashed - thereby there can be more than one value > that hashes out to the same value. > > Simple Example: I have a decimal number that needs to be encrypted if > A=0, b=1,...j = 9, k = 0, l = 1, then I can have multiple values that > evaluate to the same number. It's similar to clock or modular > arithmetic. > > BJL = 191 > LTL = 191 > > > Matthew Small > IT Supervisor > Showstopper National Dance Competitions > 3660 Old Kings Hwy > Murrells Inlet, SC 29576 > 843-357-1847 > http://www.showstopperonline.com > > -----Original Message----- > From: Bryan Stevenson [mailto:[EMAIL PROTECTED]] > Sent: Wednesday, November 20, 2002 3:25 PM > To: CF-Talk > Subject: Encryption gurus please read > > Hey All, > > I'm not entirely sure why I'm getting the results I am, so I'll ask this > question: > > Why is it that the returned encrypted value can vary even though the > string > being encrypted and the key used remains constant (i.e. when encrypting > "yeehaw" with the key "boohoo" will not always return the same encrypted > value)? > > BTW I've tested this situation against cf_cryp, cf_crypt, and Encrypt() > > TIA ;-) > > Bryan Stevenson B.Comm. > VP & Director of E-Commerce Development > Electric Edge Systems Group Inc. > t. 250.920.8830 > e. [EMAIL PROTECTED] > > --------------------------------------------------------- > Macromedia Associate Partner > www.macromedia.com > --------------------------------------------------------- > Vancouver Island ColdFusion Users Group > Founder & Director > www.cfug-vancouverisland.com > > > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~| Archives: http://www.houseoffusion.com/cf_lists/index.cfm?forumid=4 Subscription: http://www.houseoffusion.com/cf_lists/index.cfm?method=subscribe&forumid=4 FAQ: http://www.thenetprofits.co.uk/coldfusion/faq Get the mailserver that powers this list at http://www.coolfusion.com
