C++Talk.NET C++ language newsgroups   Archives   FAQ   Search   Memberlist   Usergroups   Register   Profile   Log in to check your private messages   Log in  C programming, need help..          C++Talk.NET Forum Index -> C++ Language (Moderated) View previous topic :: View next topic   Author Message Tiza Naziri Guest Posted: Mon Mar 14, 2005 9:02 am    Post subject: C programming, need help.. Hi, I'm Siti Zarina from Malaysia. Currently I involve in a research project on Advanced Encryption Standard (AES). I'm not really good in C/C++ programming. I need some advice on how to represent the finite field GF(2^ operations (such as addition, inversion, multiplication) in binary representation in C language. Another thing is how to represent the pseudocode for generating multiplicative inverse below: remainder[1] = f(x) remainder[2] = a(x) auxiliary[1] = 0 auxiliary[2] = 1 i = 2 do while remainder[i] <> 1 i = i + 1 remainder[i] = remainder(remainder[i-2] / remainder[i-1]) quotient[i] = quotient(remainder[i-2] / remainder[i-1]) auxiliary[i] = quotient[i] * auxiliary[i-1] + auxiliary[i-2] inverse = auxiliary[i] For AES, the f(x) = x^8 + x^4 + x^3 + x + 1. Consideration and help is greatly appreciated. Thank you. Regards. Siti Zarina [ See http://www.gotw.ca/resources/clcm.htm for info about ] [ comp.lang.c++.moderated. First time posters: Do this! ] Back to top Ben Hutchings Guest Posted: Mon Mar 14, 2005 9:34 pm    Post subject: Re: C programming, need help.. Tiza Naziri wrote: Quote: Hi, I'm Siti Zarina from Malaysia. Currently I involve in a research project on Advanced Encryption Standard (AES). I'm not really good in C/C++ programming. I need some advice on how to represent the finite field GF(2^ operations (such as addition, inversion, multiplication) in binary representation in C language. snip C and C++ are quite different languages. A natural implementation of an algorithm in C++ may well not be valid C code. If you need C code, this is not the place to ask. -- Ben Hutchings Having problems with C++ templates? Your questions may be answered by <http://womble.decadentplace.org.uk/c++/template-faq.html>. [ See http://www.gotw.ca/resources/clcm.htm for info about ] [ comp.lang.c++.moderated. First time posters: Do this! ] Back to top Marcin Mañk Guest Posted: Tue Mar 15, 2005 8:34 pm    Post subject: Re: C programming, need help.. "Tiza Naziri" <watija (AT) yahoo (DOT) com> wrote Quote: Hi, I'm Siti Zarina from Malaysia. Currently I involve in a research project on Advanced Encryption Standard (AES). Hello There are many C implementations of AES on the web (from very verbose to very speed-optimized) . Browsing the code would give you many hints. Also try searching under 'rijndael' . Greetings Marcin [ See http://www.gotw.ca/resources/clcm.htm for info about ] [ comp.lang.c++.moderated. First time posters: Do this! ] Back to top Display posts from previous: All Posts1 Day7 Days2 Weeks1 Month3 Months6 Months1 Year Oldest FirstNewest First         C++Talk.NET Forum Index -> C++ Language (Moderated) All times are GMT Page 1 of 1   Jump to: Select a forum C/C++----------------C LanguageC Language (Moderated)C++ Language (Moderated)C++ language (comp.lang.c++)C++ language, library and standards Non-English C/C++ Newsgroups----------------C++ (German)C++ (French)  You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot vote in polls in this forum Powered by phpBB © 2001, 2006 phpBB Group SEO toolkit © 2004-2006 webmedic.