Lab1-Introduction to Virtualization and VMWare

It is a software implementation of a machine (computer) that executes programs like a real machine. Virtualization technology is a simulation program which is simulate and create another virtual pc or windows in already windows in our machine. The user especially software developer that like to testing other operating system environment will choose this techniques because it did not crash the real operating system that install inside computer.

VMWare will create the image disk that will be use to acting like real hard drive and the extension file will be register as .vmdk. Inside the VMWare, the network connection can be configure in two way which is bridge option allow the virtual computer to direct access to external network. With this option, the virtual machine will have different ip address from the real machine ip address. this is different from the other option that is host-only. This option need user to assign the ip address for the virtual machine and have limitation, to use the network by the virtual pc is only to access among virtual machine if let say there have the other virtual machine installed together.

Basic Cryptography

It is a technique that has been use to hiding information from other people, and can be access by certain people only...

It is been use to :
1. scramble data in storage.
2. transmit data in the internet.
3. prevent from the user to understand the real message or information in the message that encrypt.

Cryptographic system is divide by 2 :
1. Cryptography : concerned with develop algorithm.
2. Cryptanalysis : obtained the meaning of encryption information.

Modern cryptography contains :

1. Mathematics to encrypt and decrypt data.
2. Concerned with principle and methods for rendering plain text unintelligible into intelligible form.
3. Used for hiding information.

Can be divide by :
1. Type of encryption operation use : substitution / transposition / product
2. number of key that been use : single key / two - key
3. way of plaintext is process : block / stream

Terms that will be use :
1. plaintext - original message
2. ciphertext - coded message
3. cipher - algorithm for transforming plaintext to ciphertext
4. key - info used in cipher known only to sender/receiver
5. encipher (encrypt) - converting plaintext to ciphertext
6. decipher (decrypt) - recovering ciphertext from plaintext
7. cryptography - study of encryption principles/methods
8. cryptanalysis (codebreaking) - study of principles/ methods of deciphering ciphertext without knowing key
9. cryptology - field of both cryptography and cryptanalysis


CRYPTANALYSIS :
It has two type : symmetric algorithm and asymmetric algorithm.

Symmetric Algorithm : sender and receiver share a common key. The encryption key is related to the decryption key. It can be divide into stream ciphers and block cipher. It need strong encryption algorithm and secret key known by sender and receiver.

Asymmetric Algorithm : It is use 2 key where the key that been use to encrypt the data is not the same key to decrypt the data. It contain 2 key which is private and public key. The message will be encrypt with public key and can only be decrypt with corresponding private key.


Method :
Substitution: mono - shifting the letter
polyalphabetic - using vigenere tableau (vigenere table)


Transposition : method encryption that shift the position according
to a regular system

Introduction of Network Security

kalo nk cite bab security(keselamatan) dlm IT ni mmg byk cara.. Semuanya bergantung pada individu@organisasi tuk gne kaedah yg mn satu..setiap device(alatan) ada kelebihan&kekurangan yg tersendri..

semua perkara blh belajar sekarang ni dlm internet...taip je http://www.google.com , semua org blh dpt maklumat@info yg di cari walaupun maklumat@info yg mungkin blh disalahgunakn.

first kelas, en zaki merangkap lecturer network security menerangkn kepentingan subjek ni:

sbb ape??

semua benda kita blh belajar dr internet walaupun untuk tujuan yg salah mcm buat virus, hack dan sebagainya..

Method (kaedah) dlm keselamatan rangkaian:

1- Prevent - blok serangan@ganguan dgn update antivirus

2- Deter - serang sblm diserang oleh hacker@virus.

3- Deflect - buat Mirroring server, supaya hacker@virus tak akan serang main server

4- Defect - buat backup untuk dokumen yg penting.

5- Recover - memulihkn ape2 kesan selepas gangguan@serangan berlaku

Dlm keselamatan rangkaian terdapat ciri2 yg perlu diambil kira :

1- Sulit (Confedential) - hanya org2 yg tertentu je yg blh access data2 yg critikal@penting...supaya maklumat seseorg@individu xterdedah kepada org len... kalo saya tau username&password online bangking org lain(org2 kaya), silap2 saya transfer duit 2 masuk dlm accaun saya...

2- Tulus (Integrity) - maklumat yg user biasa nmpk elok je..saya percaya, semua org mst pernah download file dr internet..mcm mn korg yakin yg file yg korang download tu xde virus ??kalo nk tau lbh lanjut bc la smp habis ek...

3- Ketersediaan (Availability) - byk mirror server..sbb kalo 1 server down(xlarat nk tampung user) server yg len blh ambik alih...kataknlah kalo server google@yahoo down & dorg xde wat server mirror, xde sorg pun yg kat dunia ni blh access google.com@yahoo.com smp la server dorg up&function mcm biasa..

Selain dr ciri2 kat atas ni. Ada lg benda yg perlu diambil kira mcm:

1- MD5 - menghasilkn "hash" yg unik mcm password dan maklumat user akn di encrypt supaya org lain xleh tau

2- Non-repudiation - kalo seseorg anta email lecturer, dia xleh berdolak-dalik@xmengaku bahawa dia yg anta dan sebagainya.

3- Denial Of Service (DoS) - selalu berlaku bila sender anta@mntk data yg besar dr server smp server xleh nk lyn user lain..cthnya kalo seseorg tau ping ke server & ubah nilai byte yg akn dihantar ke server tu dlm 1 masa...server itu akn overloaded&down.

4- Security Policy - buat 1 rule yg selamat..cth kalo dlm win xp..kalo nk share folder@file, khaskn hanya org2 yg terttu shj blh access.

Terdapat 2 jenis serangan@ganguan:

1- Passive - biasanya serangan bentuk ni xkacau fungsi operating system (sistem pengoperasian)..just untuk tgk sahaja data yg di capture&xkacau data2 tersebut.

2- Active - serangan jenis ni akan kacau fungsi operating system (sistem pengoperasian) dr berfungsi dgn baik seperti virus

p/s: phm drpd note BI+dr tenet..ayat agak tunggang-langgang...kalo xphm, mntk maap..

Pengenalan

Dunia sekarang ni..xsemua benda blh terselamat lg2 yg berkaitan dgn network (rangkaian) yg sekarang ni hampir semua org gne tuk buat kerja @ aktiviti seharian yg berkaitan dgn network&internet mcm banking, shopping dan yg sewaktu dengannya..