Tagged: Crypto Toggle Comment Threads | Keyboard Shortcuts

  • CG 2:15 pm on February 26, 2013 Permalink | Reply
    Tags: coding theory, Crypto   

    Crypto vs Code 

    Cryptography is the study of mathematical techniques related to aspects of information security such as confidentiality, data integrity, entity authentication, and data origin authentication. [Handbook of Applied Cryptography – Alfred J. Menezes Paul C. van Oorschot Scott A. Vanstone]

    crypto block diagram

    Coding is needed for efficient reliable digital transmission and storage. [Error Control Coding – Shu Lin, Daniel J. Costello]. Coding theory is is the study of the properties of codes and their fitness for a specific application. Codes are used for data compression, cryptography, error-correction and more recently also for network coding. Codes are studied by various scientific disciplines—such as information theory, electrical engineering, mathematics, and computer science—for the purpose of designing efficient and reliable data transmission methods. This typically involves the removal of redundancy and the correction (or detection) of errors in the transmitted data. [Wikipedia]

    coding block diagram

    Advertisements
     
  • CG 10:11 am on April 3, 2010 Permalink | Reply
    Tags: Crypto, Fun, Misc   

    Cryptography is… 

    ha ha ha ha…. funny descriptions about cryptography by another frustated graduate student on cryptography 😀

     
  • CG 5:29 pm on December 29, 2008 Permalink | Reply
    Tags: Crypto,   

    Which class to use? 

    This is the class structure of Crypto++ Library

    picture-1

    And then when I’m going to implement PK_Encryptor, which one to use???

    picture-2

    Which base class to use, when to implement, what scheme to choose? Still not clear which are the abstract classes. This library is superb but makes my head going to explode 😀

     
    • Budi Rahardjo 10:57 pm on December 29, 2008 Permalink | Reply

      Unfortunately, I can’t tell just by looking at the pictures. Gotta dig deeper into the library, which I don’t have. ha ha ha.

      I suspect you have choices (of classes to use). Which one to choose? Well, I guess you have to understand all of them (at least at superficial level – why there are more than one ways to do it) or pick one and hope that it is the best for case at hand. 😀 ha ha ha.

    • CG 2:36 am on December 30, 2008 Permalink | Reply

      @BR: actually I already have examples of “optimal” implementation and i was digging out to find out how to implement it differently and trying to figure out the structure of the classes and surprised that the library provides tons of classes i don’t understand!

  • CG 2:15 am on November 17, 2008 Permalink | Reply
    Tags: , Crypto,   

    Compiling Crypto++ 

    picture-3

    Has successfully compiled Crypto++ (pfffh, finally 😉 ). I made a very simple code (above), and standard g++ command for compiling did not work, until the library being installed to the library directory.

    Here’s how to install the crypto package:

    1. mkdir crypto
    2. mv cryptopp552.zip ./crypto
    3. cd crypto
    4. unzip cryptopp552.zip
    5. make
    6. sudo cp libcryptopp.a /usr/lib/
    7. sudo mkdir /usr/include/cryptopp
    8. sudo cp *.h /usr/include/cryptopp/

    Then compile it:

    g++ -lcryptopp cryptopptest.cpp

    And run it:

    ./a.out

    I decide to do some experiments using Crypto++ for the following reasons:

    1. It supports ECDSA, ECDH, ECIES
    2. It supports both binary and prime curves
    3. The library comes with domain parameters defined by NIST and SECG
    4. Great support for manipulating data
    5. Precomputation is supported
    6. Crypto++ is trying to receive NIST’s certification of ECDSA
     
    • Budi Rahardjo 7:51 am on November 17, 2008 Permalink | Reply

      Actually you don’t have to put all the libraries in the standard directory. You could use the “-L” switch for the library location and “-I” switch for the header location. For example, if your library and include files (header) are in “/home/cg/cryptolib”, that is the structure is something like this:

      /home/cg/cryptolib/include/*.h
      /home/cg/cryptolib/libcryptopp.a

      The compile command is like this:

      g++ -I/home/cg/cryptolib/include -L/home/cg/cryptolib cryptopptest.cpp -lcryptopp

      Have fun.

    • CG 9:37 am on November 17, 2008 Permalink | Reply

      @BR: what i did was totally different!

      g++ -L/Users/chika/Documents/CG/Library/Crypto++/ -lcryptoopp552 cryptopptest.cpp

      i didn’t know that i have to include the include dir 😀

    • tetangga@sebelah.com 11:52 am on November 17, 2008 Permalink | Reply

      walah…..pasti masih main digger ama pacman, jadi inget waktu zaman turbo c ….
      kapam mau mda
      walaupun bisa ngetik cepat sampai 120WPM tapi sebaiknya tenaga dan waktu di hemat, coba
      pekakas seperti make
      atau GBS

      tapi seperti biasa “A journey of a thousand miles begins with a single step”…..good job (gaya pak cris)

    • tetangga@sebelah.com 11:57 am on November 17, 2008 Permalink | Reply

      alah si ibu pasti masih main digger ama pacman, liat postingannya jadi inget zaman pake Borland Turbo C,
      kapan mau Model Driven Architecture nya 😛
      biar egak pegel ngetik coba pake make (http://www.gnu.org/software/make/) atau GBS (http://sources.redhat.com/autobook/)

    • tetangga@sebelah.com 12:01 pm on November 17, 2008 Permalink | Reply

      pake make atau GBS atuh

    • Budi Rahardjo 1:07 pm on November 17, 2008 Permalink | Reply

      nanti kalau udah kompleks baru pakai Makefile 😀

    • tetangga@sebelah.com 6:40 am on November 18, 2008 Permalink | Reply

      kalau bikin softwarenya compile driven 🙂 selalu komplek.
      mengetik “make” 100 kali per jam pasti lebih nyaman dibanding mengetik “g++ -I/home/cg/cryptolib/include -L/home/cg/cryptolib cryptopptest.cpp -lcryptopp” perjam :))

    • Kavita 4:41 pm on November 16, 2010 Permalink | Reply

      When I try to install cryptopp on gcc compiler it is saying the following error
      g++: cryptopptext.cpp : no such file or directory

      pls help me in this regard

      Kavita

      • CG 9:32 am on November 17, 2010 Permalink | Reply

        have you followed the instructions above? check if it’s installed in the wrong directory.

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