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                KEYS


In the first session we learnt about passwords, they are
also known as keys.

Our Keys in the exercises had 2 digits,
   or in key terms 2 teeth.


A normal household or car key has 5 teeth.


But in computer encryption we use a key with 128 bit key,
  that would look like this.


A normal key performs 2 functions:
	
	It opens a locks

	It locks a lock

This known a synchronous process


 OPEN                                                      CLOSE

		SAME KEY
          this is SYNCHRONOUS encryption
With computers the process is slightly different. You use 2 keys.

one to open


one to close


The good news is that you can swap their functions.

If a document is unlocked you can lock it with either key, but
you must use the other key to unlock it.




 OPEN  with one key                CLOSE  with the other key

		DIFFERENT KEYS
                      this is ASYNCHRONOUS encryption
 Let look at how the Government passed  Secret messages before computers.
Show me now 

With computers, you have two keys, 128bit keys.

A Private Key - Which never leaves your computer

		and

A Public Key - Which you give to other computers so they can send 	  
       you a coded, secure, message.
Show me now
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