Updates from March, 2013 Toggle Comment Threads | Keyboard Shortcuts

  • CG 9:17 pm on March 30, 2013 Permalink | Reply
    Tags: arithmetic, , , reduction,   

    Polynomial Basis Squaring 

    Finally have successfully found some spare time to do coding to solve this polynomial squaring:

    OLYMPUS DIGITAL CAMERA

    And this is the result, x^5 + x + 1 :

    Screen shot 2013-03-30 at 8.58.52 PM

    Advertisements
     
    • rudi 9:37 pm on May 30, 2013 Permalink | Reply

      bu, akan lebih cantik kalo nulis polinomnya pake latex,
      x^5 + x+1

      • CG 11:00 am on May 31, 2013 Permalink | Reply

        iya belum sempet dirapihin 😀 biasanya saya pake latex for wordpress

    • Akshay 11:18 pm on July 26, 2013 Permalink | Reply

      Hey please mail me this complete C code. sorry I’m not execute this ….please help me…please ..

  • CG 2:07 pm on March 15, 2013 Permalink | Reply  

    Why Python? 

    Our research group is developing a library for finite field operations on very long bits, so we start gathering information about the performance of Python on scientific programming, big numbers especially for cryptography.
    Here are some important links related to Python for scientific and cryptography implementation:

    1. http://www.tutorialspoint.com/python/python_numbers.htm – about Python number representations
    2. https://pypi.python.org/pypi/PyECC – a module for implementing Elliptic Curve Cryptography
    3. http://theunixgeek.blogspot.com/2008/09/c-vs-python-speed.html – Python compared to C
    4. http://www.linuxjournal.com/magazine/use-python-scientific-computing – the use of Python for scientific computing
    5. http://scipy-lectures.github.com/ – Python Scientific Lecture Notes
    6. http://www.scientificpython.net/ – Scientific Computing with Python
    7. http://wiki.python.org/moin/NumericAndScientific – list of modules and tools for various implementation in Python
    8. http://ubuntuforums.org/showthread.php?t=1581805 – Python power for large numbers
    9. http://programmers.stackexchange.com/questions/128589/how-to-handle-large-numbers – handling big numbers with Python
    10. http://www.daniweb.com/software-development/python/threads/364584/very-large-numbers – library for big numbers in Python
    11. http://www.daniweb.com/software-development/python/threads/364584/very-large-numbers – Python can handle very big numbers
    12. http://code.google.com/p/ecc4pys60/wiki/Roadmap – Elliptic Curve Cryptography implementation on S60 using Python
    13. https://gist.github.com/bellbind/1414867 – Elliptic Curve Cryptography implementation in Python
     
    • Tafta 5:08 pm on March 16, 2013 Permalink | Reply

      The title doesn’t match the content, please dech (pake helm biar ga ditampar)

      • CG 7:27 pm on March 16, 2013 Permalink | Reply

        *tempiling sampe kepalanya lepas*

  • CG 12:40 pm on March 8, 2013 Permalink | Reply  

    Python: Converting String to Binary 

    A simple code on how to convert string to binary, accessing array string and performing shift operation on binary

    
    #!/usr/bin/python

    a_str = ‘10110011’
    b_str = “00101010”
    a_bin = int(a_str, 2)
    b_bin = int(b_str, 2)

    print “a “, int(a_bin), a_str
    print “b “, int(b_bin), b_str
    print “a[0] “, a_str[0]
    print “b[0:3]”, b_str[0:3]

    #print “c “, c, bin(c)[2:]

    print “a << 2 “, a_bin << 2, bin(a_bin << 2)[2:]
    print “b >> 2 “, b_bin >> 2, bin(b_bin >> 2)[2:]

    The result:

    Screen shot 2013-03-08 at 12.37.48 PM

     
    • tinykuya 3:02 pm on March 15, 2013 Permalink | Reply

      ternyata dari string diconvert dulu ke int, terus diconvert lagi ke binary.. ya ya ya.. saya sempat berpikir operasi binernya dalam bentuk array 😀 kalau seperti ini, masuk akal.

      terima kasih bu.

      • CG 3:55 pm on March 15, 2013 Permalink | Reply

        sip mudah2an berguna 😉

  • CG 3:32 pm on March 7, 2013 Permalink | Reply
    Tags: bit operations,   

    Python: Bit Operations 

    Basic bit operations in Python:

    
    #!/usr/bin/python 
    
    a = 60            # 60 = 0011 1100 
    b = 13            # 13 = 0000 1101 
    c = 0
    
    print "a = ", (bin(a)[2:]);
    print "b = ", (bin(b)[2:]);
    
    c = a & b;        # 12 = 0000 1100
    print "a & b = ", (bin(c)[2:]);
    
    c = a | b;        # 61 = 0011 1101 
    print "a | b = ", (bin(c)[2:]);
    
    c = a ^ b;        # 49 = 0011 0001
    print "a ^ b = ", (bin(c)[2:]);
    
    c = ~a;           # -61 = 1100 0011
    print "~a = ", (bin(c)[2:]);
    
    c = a << 2;       # 240 = 1111 0000
    print "a <> 2;       # 15 = 0000 1111
    print "a >> 2 = ", (bin(c)[2:]);
    

    Result:
    Screen shot 2013-03-07 at 3.28.10 PM

    An interesting link about bit operation algorithm implementation in Python is here.

     
c
Compose new post
j
Next post/Next comment
k
Previous post/Previous comment
r
Reply
e
Edit
o
Show/Hide comments
t
Go to top
l
Go to login
h
Show/Hide help
shift + esc
Cancel