Encryption

Not all good

History is littered with people who sent fatally indiscrete messages because they though they had invented an unbreakable code.

The encryption used today is only secure because it is very inconvenient to factorise a number made up by multiplying very large prime numbers. It used to be nearly impossible to break by brute force, but as computers have got faster it has become feasible. Old 40 bit keys can apparently be broken in about a week. 128 bit ones allegedly would take longer than the age of the universe ... on today's hardware.

Using tricks rather than brute force, by sneaking some Javascript onto the page, exploiting some TCP weaknesses, or hacking into one of the Digital Certification companies, your secure data can apparently be broken into in about half an hour if anyone really wants to.