Xref: utzoo comp.lang.pascal:483 sci.crypt:686 Path: utzoo!mnetor!uunet!husc6!rutgers!mcnc!ecsvax!wmcb From: wmcb@ecsvax.UUCP (William C. Bauldry) Newsgroups: comp.lang.pascal,sci.crypt Subject: Re: Implimenting this system... Message-ID: <4284@ecsvax.UUCP> Date: 9 Dec 87 14:20:34 GMT Reply-To: wmcb@ecsvax.UUCP (William C. Bauldry) Organization: UNC Educational Computing Service Lines: 28 Keywords: Public Key systems In article <291@caus-dp.UUCP> marcos@caus-dp.UUCP (Marcos R. Della) writes: >the section that says T = (C ^ D) MOD K. The problem I face is that D is >a large number and anything taken to a large number is rediculous in size. > >Does someone have a fix that will make this a better system or maybe >another method that might not be as secure, but will still work on the >same principle of the encrypt and decrypt keys? > >Any help would be appreciated... > >Marcos R. Della Aside from the usual pointers to represent the power in terms of squares and take mod k at each opportunity in intermediate calculations, the main thought to keep in mind is the security of Public Key systems is based on the *difficulty* of arithmetic (in particular factoring large numbers) that comes up in en/de-crypting. i.e. it can't be too easy or it's not secure. If your not really worried about security, then instead of the system above (based on the RSA scheme) you could switch to a Trapdoor type of coding where the arithmetic is much simpler - back in 1976/7 Scientific American had a very good article on both these systems. Best of luck. Bill Bauldry Dept of Math Sci Appalachian State U Boone, NC