Well, I believe general usage describes a hash function as 1-way (i.e. non-bijective), whereas an encryption function is 2-way. That's how I've always seen the terms used, but I could be wrong.
-- Mosh Teitelbaum evoch, LLC Tel: (301) 625-9191 Fax: (301) 933-3651 Email: [EMAIL PROTECTED] WWW: http://www.evoch.com/ > -----Original Message----- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]] > Sent: Wednesday, November 20, 2002 4:58 PM > To: CF-Talk > Subject: RE: Encryption gurus please read > > > yes, I always thought that an encryption or hash function had to be a > bijective function. > > Doug > > >-----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 Structure your ColdFusion code with Fusebox. Get the official book at http://www.fusionauthority.com/bkinfo.cfm
