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 What
is e-TS?
Why do we need e-TS?
How does e-TS work?
What is the technology behind?
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Cryptography is the science
of applying complex mathematics to ensure the security of information
transactions.
Encryption and
decryption
Cryptography consists of encryption and decryption. Encryption means
to change a comprehensible plain text message into an incomprehensible
cipher text message so that unauthorized people, even those have
access to the encrypted data, cannot understand the message. Decryption
is the opposite of encryption; it is to recover the hidden data
back to the original form so that it can be understood.
Algorithm and key
To encrypt/decrypt a message, a cryptographic algorithm is used.
The algorithm is like a lock that protects the contents of the data.
As a conventional key is needed to operate the lock, a key for the
algorithm is also required to change a plain text into a cipher
text and vice versa. In the following example, if you know the algorithm,
you can find out the key with 26 attempts at most. However, the
more complex the cryptographic algorithm, the more difficult it
becomes to get the information in the encrypted data without access
to the key.
Symmetric and asymmetric cryptography
There are two main classes of cryptographic algorithm, symmetric
and asymmetric. The above example is symmetric cryptography, which
uses the same key for both encryption and decryption. Asymmetric
cryptography uses a mathematically related key pair-a public key
that is published and a private key that is kept secret. Data is
encrypted with one key and can only be decrypted with the other
key in the same pair.¡@Please refer to Public
Key Infrastructure.
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