Unfortunately, it
does not work
The Babel of Cryptography 39
cryptography is that a secret should be safe even if the attacker
knows in detail the algorithm that was used for performing the
encryption. The mathematical functions employed in the scrambling
must respond to very rigid canons of robustness and are
the result of a process of sophistication that lasted hundreds of
years.
In its simplest form, an encryption algorithm can be seen as a
black box with two entrances and one exit. In one entrance, you
put the text you want to protect (the plaintext, or clear text); on
the other, you enter a key, that is to say a string of characters of
a certain length. Turning the ???encrypt??? knob will produce at the
exit an unreadable fragment of text (the ciphertext), which is
actually a nontrivial combination of the plaintext and the key. If
an attacker acquires the ciphertext but not the key, he will need
to be very lucky or very patient to access the content. Trying all
the key combinations (known as a brute-force attack) against a
modern algorithm can literally take amounts of time on the order
of geological. If somebody owns the key, however, the decryption
operation is straightforward.
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