|
Science Forum Index » Cryptography Forum » BigNums fpr Visual C++ .Net
Page 1 of 1
|
| Author |
Message |
| dotti |
 Posted: Sat Jan 03, 2004 2:39 pm |
|
|
|
Guest
|
I'm trying to write a small demo program for RSA.
Bit the long integer is to short for needed exponential functions.
Does anyone know how to handle very large numbers in C++?
thx
dotti |
|
|
| Back to top |
|
| Tom St Denis |
| Posted: Sat Jan 03, 2004 2:41 pm |
|
|
|
Guest
|
"dotti" <frysixteen@hotmail.com> wrote in message
news:bt75oq$5rd$00$1@news.t-online.com...
Quote: I'm trying to write a small demo program for RSA.
Bit the long integer is to short for needed exponential functions.
Does anyone know how to handle very large numbers in C++?
Not strictly C++ but it is C [should build in C++ mode]
http://math.libtomcrypt.org
;)
Tom |
|
|
| Back to top |
|
| Tom St Denis |
| Posted: Sat Jan 03, 2004 2:41 pm |
|
|
|
Guest
|
"dotti" <frysixteen@hotmail.com> wrote in message
news:bt75oq$5rd$00$1@news.t-online.com...
Quote: I'm trying to write a small demo program for RSA.
Bit the long integer is to short for needed exponential functions.
Does anyone know how to handle very large numbers in C++?
Not strictly C++ but it is C [should build in C++ mode]
http://math.libtomcrypt.org
;)
Tom |
|
|
| Back to top |
|
| Giuliano Bertoletti |
| Posted: Sun Jan 04, 2004 4:51 am |
|
|
|
Guest
|
On Sat, 3 Jan 2004 20:39:05 +0100, "dotti" <frysixteen@hotmail.com>
wrote:
Quote: I'm trying to write a small demo program for RSA.
Bit the long integer is to short for needed exponential functions.
Does anyone know how to handle very large numbers in C++?
thx
dotti
Victor Shoup's NTL is one of the best libraries available for doing
number theory. It's however distributed under a GNU license, which may
or may not suit your needs (in terms of a possible redistribution of
your program, I mean).
Consider also that's not directly related to cryptography, but only to
computer algebra.
http://www.shoup.net/
Giulio. |
|
|
| Back to top |
|
| Brian Gladman |
| Posted: Sun Jan 04, 2004 5:13 am |
|
|
|
Guest
|
"dotti" <frysixteen@hotmail.com> wrote in message
news:bt75oq$5rd$00$1@news.t-online.com...
Quote: I'm trying to write a small demo program for RSA.
Bit the long integer is to short for needed exponential functions.
Does anyone know how to handle very large numbers in C++?
For a demonstration program you could use a C++ class that keeps the decimal
digits of your numbers in arrays of integers. You could then implement
school arithmetic for addition, subtraction, multiplication, division etc.
yourself using C++ operator overloading for the normal arithmetic operators.
This is not hard to do if efficiency is not an issue and the coding involved
would give you a feel for some of the real problems involved whilst also
forming a visible part of the demonstration. For demonstration purposes
this is likely to be better than using a pre-existing library since these
will generally require you to focus on issues that will divert you from your
main aim of demonstrating the operation of RSA.
My suspicion is that something like this probably already exists if you have
the patience to search for it on Google.
Brian Gladman |
|
|
| Back to top |
|
| |
