Hacking the Xbox

Chapter 9 - Sneaking in the Back Door 145
That single location can be pre-loaded with a follow-up jump instruction
back into any piece of user code using the previously discussed jam table
codes. The Xbox hacking community had come together in a heroic
effort and cracked Xbox security version 1.1 in three days. A separate
effort, no less valiant, by Xecuter had also cracked the security in the
same time frame.
The first moral of this story is that security is only as strong as its weakest
link. While there is little doubt about the robustness of the RSA cipher
and the SHA-1 hash for digital signature purposes, these were not the
only elements of the security system. The TEA cipher used to extend the
secure boot ROM’s trust sphere into the FLASH ROM had flaws that
allowed hackers to walk around the strong digital signature algorithms.
This leads us to our second moral: complexity breeds weaknesses.
Complex systems are difficult to design, test, and analyze. The version 1.1
security for the Xbox was probably implemented on a short fuse, so
Its like that picture on the “Ascent of Man,” from Nethanderal
relative branch computation through to Homo Erectus with
his virtual functions.
Alongside this I began to explore digital hardware design,
again teaching myself from experience. I discovered that
hardware and software are two sides of the same coin, although
they are treated completely separately in education.
It’s really an implementation detail whether you choose to
make your logical function in software or in hardware, or some
mixture of the two. Having a foot in both camps gives greater
insight into the nature of design: for example, C++ can be
said to borrow many concepts from electronics in terms of the
importance of interfaces.
Recently before becoming interested in the Xbox I had been
working for a US-owned company with an office in Oxford,
doing many jobs but the last one was designing smartcard
silicon. Although the design was interesting and there were
some great people working in the trenches there, I became
increasingly despondent about the politics and problems with
the management. Nor did it help that despite being spread
across several projects, I was paid 2/3rds the salary of staff in
San Jose simply because I was based in the UK. And don't get
me started about the patents they had from me with no reward.
In December 2001 I discovered that integrity was more
important than money, resigned, and decided to go back to
working for myself.
I had been rather tenderized by some unpleasant experiences
on leaving this company, while digesting these I found myself
snagged by the vast difference in outlook between the ugly,
grabbing, controlling instincts of your average company involved
in Intellectual Property, and the nature of GPL projects
and the people involved in encouraging a reduction in the
severity of patent and copyright laws. As time went on I increasingly
came to see Microsoft, and the previous company
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