Engineering Math, Period 2, 4 Dec '09
Mohinder was at the front of a classroom that had an uncanny resemblance to a computer lab; if one which had sprouted typewriters on steroids, interconnections of cogs and valve banks amongst the more usual array of desk and laptops.
"If you want to hide information more securely than just by concealing its location, then you need to change the information itself. Passing on 'The elk flies at midnight' can mean something else entirely to the right listener," said Mohinder. Or warn them to duck when out that night. Carrying an umbrella.
"Cryptographers have devised, and broken, a number of code systems," he said, passing out a few examples. "From the simple - the replacing of one letter with another, transposing groups of letters and those ciphers based on the sender and recipient having the same edition of the same book." Mohinder elaborated, encoding and decoding, with increasing complex ciphers.
"The complexity of some cipher keys has become so great that breaking them may be impossible," Mohinder closed, "Barring quantum computing or breaking the chain with the user. Now, it's time to try your techniques at coded communication."
[OCD has been decoded!]
"If you want to hide information more securely than just by concealing its location, then you need to change the information itself. Passing on 'The elk flies at midnight' can mean something else entirely to the right listener," said Mohinder. Or warn them to duck when out that night. Carrying an umbrella.
"Cryptographers have devised, and broken, a number of code systems," he said, passing out a few examples. "From the simple - the replacing of one letter with another, transposing groups of letters and those ciphers based on the sender and recipient having the same edition of the same book." Mohinder elaborated, encoding and decoding, with increasing complex ciphers.
"The complexity of some cipher keys has become so great that breaking them may be impossible," Mohinder closed, "Barring quantum computing or breaking the chain with the user. Now, it's time to try your techniques at coded communication."
[OCD has been decoded!]