Security Engineering: A Guide to Building Dependable Distributed Systems, Second Edition

Legal Notice

I cannot emphasize too strongly that the tricks taught in this book are intended only to enable you to build better systems. They are not in any way given as a means of helping you to break into systems, subvert copyright protection mechanisms, or do anything else unethical or illegal.

Where possible I have tried to give case histories at a level of detail that illustrates the underlying principles without giving a 'hacker's cookbook'.

Should This Book Be Published at All?

There are people who believe that the knowledge contained in this book should not be published. This is an old debate; in previous centuries, people objected to the publication of books on locksmithing, on the grounds that they were likely to help the bad guys more than the good guys.

I think that these fears are answered in the first book in English that discussed cryptology. This was a treatise on optical and acoustic telegraphy written by Bishop John Wilkins in 1641 [805]. He traced scientific censorship back to the Egyptian priests who forbade the use of alphabetic writing on the grounds that it would spread literacy among the common people and thus foster dissent. As he said:

It will not follow that everything must be suppresst which may be abused... If all those useful inventions that are liable to abuse should therefore be concealed there is not any Art or Science which may be lawfully profest.

The question was raised again in the nineteenth century, when some well-meaning people wanted to ban books ...