iphone3gs

My brother sent me an iphone 3gs at December 11th 2010 since he brought an iphone4. Before I received this 3gs, I just treated it as a cell phone with some trivial functions, such as games and mp3 player. After I received this 3gs, I aware that I was wrong.

Smart phones are light-weight computers. For example, 3gs is a computer with 600MHz CPU, 256MB RAM, and 32GB(optional) flash memory. A 3gs is significantly faster than a pentium computer. You can imagine that it may produce a 1024-bit RSA key within several seconds.

The operating system of iphones is named iOS. The iOS is extremely closed because it can only run applications downloaded from iTunes store. An iphone can never run any custom application unless you publish your applications in iTunes store. Apple examines all applications that are going to be published in iTunes. Applications will deny to be published if they cannot obey apple's rules. For example, illegal or malicious applications will be avoided to be published. Apple claims this mechanism ensures security, however, I never think so. The closed system is extremely inconvenient for me.

Fortunately, iOS is not an absolutely secure operating system. Hackers attempts to jailbreak iOS by design flaws of iOS. A jailbroken iOS reveals all iOS's function. You can treat an iOS as an unix-like operating system. In order to do my jobs efficiently, I downloaded well-written jailbreak-tools to jailbreak my 3gs. My 3gs can run bash(unix shell), gcc(compiler) and more so far. It means I can run almost applications that I want.

More experiences may be shared when I want to practice my writing in English.