Simulasi Kode Hamming menggunakan modulasi BPSK


Kode Hamming adalah salah satu metode untuk error correction. Kali ini kita ingin mencoba simulasi melalui simulink bagaimana jika Hamming digunakan pada modulasi digital seperti BPSK yang ditransmisikan melewati kanal AWGN. Berikut Simulasi nya:
Screenshot from 2016-02-29 13:17:44

Screenshot from 2016-02-29 13:18:59

Kode Hamming yang kita gunakan adalah 31,26 disini nampak BER menurun setelah melewati Eb/No = 4, dan setelah Eb/No =8 sudah tidak terdapat BER. Berikut file simulink dan mfile

Simulink File: https://www.dropbox.com/s/azcw1frcx8s1hpb/Lab_PKU_BPSK_Hamming.mdl?dl=0

mfile: https://www.dropbox.com/s/sr348gtuij8sctk/Run_puk.m?dl=0

note: run mfile after that you can get the graphic

Algoritma Kriptografi apa yang harus kita pilih?


When it comes to evaluating and choosing algorithms, people have several alternatives:
— They can choose a published algorithm, based on the belief that a published algorithm has been scrutinized by many cryptographers; if no one has broken the algorithm yet, then it must be pretty good.
— They can trust a manufacturer, based on the belief that a well-known manufacturer has a reputation to uphold and is unlikely to risk that reputation by selling equipment or programs with inferior algorithms.
— They can trust a private consultant, based on the belief that an impartial consultant is best equipped to make a reliable evaluation of different algorithms.
— They can trust the government, based on the belief that the government is trustworthy and wouldn’t steer its citizens wrong.
— They can write their own algorithms, based on the belief that their cryptographic ability is second-to-none and that they should trust nobody but themselves.

Any of these alternatives is problematic, but the first seems to be the most sensible. Putting your trust in a single manufacturer, consultant, or government is asking for trouble. Most people who call themselves security consultants (even those from big-name firms) usually don’t know anything about encryption. Most security product manufacturers are no better. The NSA has some of the world’s best cryptographers working for it, but they’re not telling all they know. They have their own interests to further which are not congruent with those of their citizens. And even if you’re a genius, writing your own algorithm and then using it without any peer review is just plain foolish.

Schneier, Bruce. Applied Cryptography, Second Edition, John Wiley & Sons, 1996

whatsapp via command line interface (yowsup)


Kali ini kita mencoba menggunakan youwsup untuk mengirim pesan atau menerima pesan via command line interface

diasumsikan python sudah terinstall di komputer anda

#step 1
#download youwsup
wget https://github.com/tgalal/yowsup/archive/master.zip
#unzip
unzip /master.zip
#cd yowsup-master

#step 2
#install youwsup
python setup.py install

#step 3 Registration
#Registrasi
yowsup-cli registration –requestcode sms –phone 62XXXXXXXX –cc 62 –mcc 510 –mnc 10
–phone 62XXXXXXXX = isi dengan nomor anda beserta kode negara tanpa “+” sebagai contoh 62812115478
–mcc 510 = isi dengan kode mcc misal telkomsel 510
–mnc 456 = isi dengan kode mnc misal telkomsel 10

#tunggu sms beberapa saat
#kirim balik kode yang didapatkan via sms
yowsup-cli registration –register 123456 –phone 49XXXXXXXX –cc 49

#Step 4 dapatkan Username dan password jika registrasi berhasil
#Username => login : nomor_telepon
#password ==> pwd : FcXXXXXXXXXXXXXXXXX-
Screenshot from 2016-02-02 19:53:21

#Selesai

Mengirim Pesan
#yowsup-cli demos -l -s nomor tujuan
yowsup-cli demos -l 62812115478:FcXXXXXXXXXXXXXXXXX= -s 62812115444 “Testing WhatsApp…”

Menggunakan interaktif mode
/yowsup-master$ yowsup-cli demos -l 62812115478:FcXXXXXXXXXXXXXXXXX= -y

setelah muncul [offline] ketik /L
[offline]:/L

setelah itu mendapatkan konfirmasi connect
Auth: Logged in!
[connected]:

ketik /help untuk mendapatkan petujuk menggunakan interaktif mode
[connected]:/help

misal ingin mengirimkan pesan
/message send 62812115444 “apa kabar?”

untuk menerima pesan akan langsung ditampilkan
misal
[62812115444@s.whatsapp.net(02-02-2016 21:01)]:[FdXXXXXXXXXXXXXXXXX] kabar baik

 

referensi:

http://manpages.ubuntu.com/manpages/wily/man1/yowsup-cli.1.html

https://github.com/tgalal/yowsup