Updates from August, 2008 Toggle Comment Threads | Keyboard Shortcuts

  • CG 7:07 pm on August 28, 2008 Permalink | Reply
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    Papers on ECC Implementation 

    Now reading

    1. D. Hankerson, J.L. Hernandez, A. Menezes, “Software Implementation of Elliptic Curve Cryptography over Binary Fields”
    2. M. Brown, D. Hankerson, J. Lopez, A. Menezes, “Software Implementation of the NIST Elliptic Curves over Prime Fields”
     
    • Budi Rahardjo 5:20 am on August 29, 2008 Permalink | Reply

      Good! Summary, please.
      Also, don’t forget to enter this into you bibliography database.

    • chikaradirghsa 3:57 pm on August 31, 2008 Permalink | Reply

      @BR: summary is in progress. already added to the bibliography database.

    • intan 1:53 pm on September 3, 2008 Permalink | Reply

      after the summary can you make a presentation in our ecc-study group about this book, please?

    • chikaradirghsa 6:45 pm on September 3, 2008 Permalink | Reply

      @intan: those are papers, not books. would be glad to give presentation, but need some time to prepare it. is 2 weeks from now ok? 😉

  • CG 7:30 pm on August 26, 2008 Permalink | Reply
    Tags:   

    back to campus 

    spend some time at the campus today. it was surprisingly gave some recharging effects.

    life must go on, so does the research 🙂

     
  • CG 8:48 pm on August 24, 2008 Permalink | Reply
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    where did i… 

    leave the last progress of my research?

    these things happening the last few days… draining me.

     
    • Budi Rahardjo 5:46 am on August 26, 2008 Permalink | Reply

      Hang on tough!
      Things happen in life.
      You’ll get it through…

    • chikaradirghsa 7:31 pm on August 26, 2008 Permalink | Reply

      @BR: thanks for being there all the time

  • CG 7:22 pm on August 22, 2008 Permalink | Reply
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    Away for a while 

    Cannot access my other blog to inform this, so i’m leaving a clue here that i might be away for a while. i’ll write about what’s happening right away after i can access the site (no personal stuff here, that’s the rule).

    Will fight to keep in focus to the research and make some progress. Sorry for not responding your comments (if there’s any) immediately 😉

     
  • CG 6:30 pm on August 20, 2008 Permalink | Reply
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    more rules ! 

    Today I received a short message from my academic advisor informing that all phd students under his supervision should do the research in campus for at least 4 hours everday (Mon-Fri) and submit progress report every week.

    Seems that it won’t be any problem at all for me, except that he mentioned about signing up attendance form everyday!! 😛

     
    • okta sihotang 1:32 pm on August 21, 2008 Permalink | Reply

      berarti anda udah phd toh ??
      salam ya master 😉

    • aprilw 1:33 pm on August 21, 2008 Permalink | Reply

      selamat berjuang 😀 … atau mau seperti di sini, minimal 10 jam sehari, mon-fri, kadang2 weekend juga 😀

    • nugie 4:26 pm on August 22, 2008 Permalink | Reply

      and tell your advisor : You have to be in the lab at least 4 hours every day and submit weekly report too…. or, I will send a recommendation letter for the top management to fire you 😀

    • chikaradirghsa 7:14 pm on August 22, 2008 Permalink | Reply

      #okta sihotang: salam juga 🙂

      #aprilw: hi hi hi.. prakteknya sih 8 jam sehari mon-fri, ditambah yang dirumah, mungkin bisa jadi 10 jam juga sih, hi hi hi dan weekend bisa semakin menggila 😀

      #nugie: good point, dude! i will do tell him :))

  • CG 5:46 pm on August 18, 2008 Permalink | Reply
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    Crypto++ Library: Exploration 

    The library is developed under Microsoft Visual C++ Environment. I got headache to see those lines of API programming using MFC, aaaaaaarghghghghgg….

    So I will just observe the inner workings and then start to build a simple code of encoding text and decrypt it  using ECC.

    Additional info:

    Crypto++ supplies 31 predefined Elliptical Curves for use with ECIES (Elliptic Curve Integrated Encryption Scheme) as specified in ANSI X9.63. These curves range in size from 112 bits to 571 bits. Encrypting a 4 byte message with a 112 bit ECIES object produces a cipher text length of 53 bytes. Encrypting the same message with an ECIES object of 34 bits will produce a 35 byte cipher text.

     
  • CG 3:33 pm on August 18, 2008 Permalink | Reply
    Tags: curve generator,   

    Curve generator 

    Have just downloaded a curve generator called ECB – Elliptic Curve Builder (and just found out that it’s executable for use under Win XP on 32-bit prosessors :(( ).

    The important thing is to find out is whether the curves generated by ECB are secure, or not?

     
  • CG 12:30 pm on August 18, 2008 Permalink | Reply
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    Crypto Library 

    Stumbled upon this page while looking for some examples of encrypting message block with ECC, then found a crypto library called Crypto++ Library.

    Will explore on how to compile and utilize the library and wondering will I end up with developing my own crypto library? We’ll see.

     
  • CG 9:46 pm on August 16, 2008 Permalink | Reply
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    Plaintext embedding on Elliptic Curve: Conclusions 

    From this paper:

    • Problems of plaintext embedding are the fundamental problems in elliptic curve public key cryptosystems.
    • A good embedding algorithm will enhance the encryption speed.
    • Plaintext embedding algorithm in binary field presented in the paper is easier to be implemented than that in prime field, and faster.
    • Applying the plaintext embedding algorithm to the storage and trasmission of points in elliptic curve can save half of the storage space and bandwidth.
     
  • CG 3:22 pm on August 16, 2008 Permalink | Reply
    Tags: jacobi symbol, plaintext embeding,   

    Jacobi symbol 

    Embedding plaintext on Elliptic Curve is no simple. The problems to solve are how to represent a block of plaintext with the form of point on elliptic curve and recover it quickly. Not any block of plaintext can be embedded to elliptic curve because about half of x has no y correspondingly.

    The common method to resolve this is by determining the quadratic residue using Jacobi symbol. If Jacobi(a) = 1, a is a quadratic residue, and if Jacobi(a) = -1, c is not a quadratic residue so the corresponding plaintext can’t be embeded to elliptic curve.

    The following is the code for calculating Jacobi symbol [thx God I took the course taught by Prof. Edy Tri Baskoro, so I’m familiar enough with this “common” mathematical method, hi hi hi]:

    /********************************************
     *  Program for calculating Jacobi symbol   *
     *                                          *
     *  CG - August 2008                        *
     ********************************************/
    
    #include <iostream>
    
    using namespace std;
    
    int jacobi(int, int);
    
    int main()
    {
        int a, n;
    
        cout << "a? ";
        cin >> a;
        cout << "n? ";
        cin >> n;
    
        cout << "\nThe Jacobi symbol is " << jacobi(a,n) << endl;
    
        return 0;
    }
    
    /* Precondition: a, n >= 0; n is odd */
    int jacobi(int a, int n) {
        int ans;
    
        if (a == 0)
            ans = (n == 1) ? 1 : 0;
        else if (a == 2) {
            switch ( n % 8 ) {
                case 1:
                case 7:
                        ans = 1;
                        break;
                case 3:
                case 5:
                        ans = -1;
                        break;
            }
        }
        else if ( a >= n )
            ans = jacobi(a%n, n);
        else if ( a % 2 == 0 )
            ans = jacobi(2,n)*jacobi(a/2, n);
        else
            ans = ( a % 4 == 3 && n % 4 == 3 ) ? -jacobi(n,a) : jacobi(n,a);
        return ans;
    }

    I test the code using example from this book, page 132. a = 6278 and n = 9975. The result is correct : -1

     
    • soni 6:03 pm on August 16, 2008 Permalink | Reply

      a itu apa? n itu apa? kenapa n harus bilangan ganjil?
      aku coba baca code-nya, ternyata ini rekursif!
      susah uy!

    • chikaradirghsa 9:09 pm on August 16, 2008 Permalink | Reply

      n itu suatu bilangan prima ganjil. a adalah bilangan integer > 0. Jacobi symbol ini juga digunakan untuk primality test.

      iya, programnya rekursif. dan coba deh lu bayangin waktu gue ujian kuliah p edy, disuruh ngitung Jacobi symbol manual! beriterasi2x dan gue salah itung dan baru sadar pas 10 menit waktu mau habis, aaaaaaaa

    • mehobbes 11:10 am on August 17, 2008 Permalink | Reply

      saya tidak mengerti kriptologi, apalagi curve elliptic.
      tapi saya sangat tertarik dengan baris-baris program Jacobi symbol ini.
      ada beberapa sintaks2x yang belum pernah saya kenali sebelumnya.

      saya salin program ini, dan saya compile ulang di komputer saya.
      semuanya lancar, bisa langsung dieksekusi tanpa error.
      hasil eksekusinya pun sama, sesuai dengan contoh.
      kemudian, saya amati baris demi baris.
      dan akhirnya saya bisa mengerti makna dari baris2x program ini.

      ternyata, sesuatu yang tidak berhubungan dengan saya, bukan berarti tidak bermanfaat.
      tidak salah kalau selama ini saya selalu mengikuti blog ini.
      chikaradirghsa, terima kasih banyak.
      you’re so gorgeous!

    • Budi Rahardjo 5:48 pm on August 17, 2008 Permalink | Reply

      versi perlnya mana? :p

    • chikaradirghsa 6:14 pm on August 17, 2008 Permalink | Reply

      #BR: bikinin! 😉

    • Firman 8:08 am on August 20, 2008 Permalink | Reply

      hare gene pake mek? 😀

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