Cloud Computing

Ketika kita membicarakan Cloud Computing, sebenarnya apakah kita membicarakan hal yang sama?

Banyak pihak memberikan definisi cloud computing dengan perbagai jenis pendapat yang berbeza-beza di sana-sini.

Wikipedia mendefinisikan cloud computing sebagai “komputer berasakan internet, kerana ia mengunakan server untuk menyediakan pangkalan data untuk menyimpan segala software serta data yang berkaitan dimana data-data yang boleh dicapai darimana komputer pada masa dan tempat yang berbeza”.

Gartner mendefinisikannya sebagai “sebuah cara komputer yang mudah dikembangkan dan lentur (fleksibel) disediakan sebagai sebuah layanan untuk pelanggan menggunakan teknologi Internet.”

Secara sederhana, Cloud Computing dapat kita bayangkan seperti sebuah jaringan listrik. Apabila kita membutuhkan listrik, apakah kita harus punya pembangkit listrik sendiri? Tentu tidak. Kita tinggal menghubungi penyedia layanan (dalam hal ini, PLN), menyambungkan rumah kita dengan jaringan listrik, dan kita tinggal menikmati layanan tersebut. Pembayaran kita lakukan bulanan sesuai pemakaian.

Kalau listrik bisa seperti itu, mengapa layanan komputasi tidak bisa? Misalnya, apabila sebuah perusahaan membutuhkan aplikasi CRM (Customer Relationship Management). Kenapa perusahaan tersebut harus membeli aplikasi CRM, membeli hardware server, dan kemudian harus memiliki tim TI khusus untuk menjaga server dan aplikasi tersebut?

Di sinilah cloud computing berperan. Penyedia jasa cloud computing seperti Microsoft, telah menyediakan aplikasi CRM yang dapat digunakan langsung oleh perusahaan tadi. Mereka tinggal menghubungi penyedia layanan (dalam hal ini, Microsoft), “menyambungkan” perusahaannya dengan layanan tersebut (dalam hal ini, melalui Internet), dan tinggal menggunakannya. Pembayaran? Cukup dibayar per bulan (atau per tahun, tergantung kontrak) sesuai pemakaian. Tidak ada lagi investasi di awal yang harus dilakukan.

http://www.infokomputer.com

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SECURITY PROCEDURES

SECURITY PROCEDURES

Computers should have alarm systems to guard them from any attacks such as viruses and data corruption. The alarm system is the security measures that we take to ensure its safety.

DATA PROTECTION
We need to protect the data in the computer as it may somehow get lost or corrupted due to some viruses or mishap like fire, flood, lightning, machine failures and even human errors.

There are a few ways to protect the information namely:
• make backup files
• detect the virus and clean the computer
• warn others on virus attacks

1) BACKUP FILES
Users can do backups of file systems by:

- keeping the duplicated files in external storage such as in the floppy disk and thumb drive
- do backup frequently

2) DETECT VIRUS AND DO CLEANUP
A computer virus is able to affect and infect the way the computer works. Viruses can be detected when we run an antivirus. We can also delete the infected files and documents.

3) WARN OTHERS ON VIRUS ATTACK
We can warn others on virus attacks or new viruses by sending e-mails to them.

DETECTING ILLEGAL ACCESS TO SYSTEMS
The computer system is able to detect any illegal access to the system by a user who does not have any authorisation. Basically, a corporation will simply use tcpwrappers and tripwire to detect any illegal access to their system. User's access will be reviewed periodically by computer operations. On going internal audits will be made to ensure detection of violations of security and unauthorised modifications to software and data .

TCPWRAPPERS
Tcpwrappers will control access at the application level, rather than at the socket level like iptables and ipchains. The system will run tcpwrappers to log access to ftp, tftp, rch, rlogin, rexec and telnet.

TRIPWIRE
Tripwire will detect and report on any changes in the thousands of strategic system files.
The system will run tripwire to determine if system files have changed.

PREVENTING ILLEGAL ACCESS TO SYSTEMS
Ways to prevent illegal access to systems:
1. Run anlpassword to make password cracking difficult.
2. Run tcpwrappers to check if the name for an ip address can be provided by DNC
3. Use a callback system to prevent unauthorised use of stolen passwords.

PREVENTING ILLEGAL ROOT ACCESS

Sudo stands for (Superuser do) and is a program in Unix, Linux and similar operating systems such as Mac OS X that allows users to run programs in the form of another user (normally in the form of the system's superuser).

Sudo allows a permitted user to execute a command as the superuser or another user, as specified in the sudoers file.

PATCH
Patch supplies small updates to software, provided that the source code is available.
Patch is a name of an UNIX utility. It applies a script generated by the different program to a set of files that allows changes from one file to be directly applied to another file.

Resources are not enough to patch all security holes that we hear about through the bugtraq list.

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RELATIONSHIP BETWEEN SECURITY THREATS AND SECURITY MEASURES

SECURITY THREADS

Security threats may come from in many forms. For example, when someone is invading your account information from a trusted bank, this act is considered as a security threat.

Security measures can be used to prevent this invader from getting the account information. For example, the bank can use a firewall to prevent
unauthorised access to its database.

MALICIOUS CODE THREATS VS. ANTIVIRUS AND ANTI-SPYWARE
Security threats include virus, Trojan horse, logic bomb, trapdoor and backdoor, and worm.

Antivirus and anti-spyware can be used to protect the computer from the threats by:
limiting connectivity
allowing only authorised media for loading data and software
enforcing mandatory access controls
blocking the virus from the computer program

HACKING VS. FIREWALL
Hacking is an unauthorised access to the computer system done by a hacker. We can use firewall or cryptography to prevent the hacker from accessing our computers.

A firewall permits limited access to unauthorised users or any activities from the network environment. Cryptography is a process of hiding information by changing the actual information into different representation, for example, an APA can be written as 7&*.


NATURAL DISASTER VS. DATA BACKUP
The natural and environmental disasters may include:
• flood
• fire
• earthquakes
• storms
• tornados

The backup system is needed to backup all data and applications in the computer. With the backup system, data can be recovered in case of an emergency.

THEFT VS. HUMAN ASPECTS
Computer theft can be of two kinds:

• can be used to steal money, goods, information and computer resources
• the actual stealing of computers, especially notebooks and PDAs

Measures that can be taken to prevent theft:

• prevent access by using locks, smart-card or password
• prevent portability by restricting the hardware from being moved
• detect and guard all exits and record any hardware transported

BE SUPSPICIOUS OF ALL RESULTS

There are many instances where non-programmers develop applications which are not built with proper understanding of software engineering practices. Data produced by such applications may not be correct and may risk corrupting data received from other sources that are not compatible with the application.

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