Achieving Privacy through Asymmetric Cryptography
How can I
achieve Privacy through Encryption with Asymmetric Cryptography?
When you start using this animation website, you are first
acting in the role of Bob. Bob has two keys: His public key is
encloesd in a website symbol ( ) - Bob has published
this key on his homepage for anyone to download. His private key,
however, is enclosed in a safe symbol ( ) - Bob keeps this
key safe from anyone else accessing this key! Since Bob's
computer is connected to the Internet, Bob can also access Alice's
public key, which she published on her homepage just like Bob
published his public key on his website.
Now Bob wants to send Alice a message which only Alice will
be
able to decrypt. In order to achieve this, Bob needs to encrypt his
message to Alice using Alice's private key. Help Bob with encrypting
and sending his message:
- Click the website-symbol () enclosing Alice's
public key in order to copy this key into the fields "use this key" of
Bob's computer.
- Next click the button "use key on message" of
Bob's computer to encrypt the message with the key you have just copied
into the fields "use this key".
- Now click the button "<<" of Bob's
computer to send the encrypted message to Alice's computer via the
public Internet.
Now it is Alice's turn to decrypt Bob's message. Click the
button "Alice's computer" of Alice's computer to switch to the role of
Alice. Then help her decrypt Bob's message:
- Click the safe-symbol () enclosing Alice's private key to
copy the key into the fields "use this key" of Alice's
computer.
- Now click the button "use key on
message"
of Alice's computer to decrypt the message with the key you have just
copied into the fields "use this key".
Voilà, Alice and Bob just exchanged a message over the
Internet with no participant being able to read the actual content of
the message. Unlike with symmetric algorithms, Alice and Bob never had
to exchange a secret key!
Task:
Alice wants to tell Bob - and Bob only! - the name
of her favourite band.
Use this animation to show what Alice and Bob do to
communicate the information safely!
Notice: This
animation only supports the encryption of lower case letters, full stop
and comma. Numbers should be spelled out such as "five" for "5"!
* The keys you find in the text fields upon loading the animation are only a proposal. There are other possible pairs of keys, such as these. If you would like to use a differen pair of keys simply edit the numbers in the text fields surrounded by the symbols for the private and public key accordingly.
(c) 2010 Andreas
Gramm
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