[This post is by Nick Kralevich, an engineer on the Android Security Team. — Tim Bray]

“Nexus S has been rooted, let the madness commence!” proclaims Engadget . “This is only possible because Android's security is crap and it's exploited easily to gain root priviledges [sic]” adds a commenter.

You’ll have to excuse me if I strongly disagree.

The Nexus S, like the Nexus One before it, is designed to allow enthusiasts to install custom operating systems. Allowing your own boot image on a pure Nexus S is as simple as running fastboot oem unlock . It should be no surprise that modifying the operating system can give you root access to your phone. Hopefully that’s just the beginning of the changes you might make.

Legitimately gaining root access to your device is a far cry from most rooting exploits. Traditional rooting attacks are typically performed by exploiting an unpatched security hole on the device. Rooting is not a feature of a device; rather, it is the active exploitation of a known security hole.

Android has a strong security strategy, backed by a solid implementation. By default, all Android applications are sandboxed from each other, helping to ensure that a malicious or buggy application cannot interfere with another. All applications are required to declare the permissions they use, ensuring the user is in control of the information they share. And yes, we aggressively fix known security holes, including those that can be used for rooting. Our peers in the security community have recognized our contribution to mobile security, and for that, we are extremely grateful.

Unfortunately, until carriers and manufacturers provide an easy method to legitimately unlock devices, there will be a natural tension between the rooting and security communities. We can only hope that carriers and manufacturers will recognize this, and not force users to choose between device openness and security. It’s possible to design unlocking techniques that protect the integrity of the mobile network, the rights of content providers, and the rights of application developers, while at the same time giving users choice. Users should demand no less.