INFORMATION SECURITY
Title: Information Security
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INFORMATION SECURITY
Information Security
Based on our discussion above, the Security Protocol provides a learning environment for
exploring secure communications protocols and the possible attacks against them.
Secure data communication requires two key elements. Cryptographic methods are used to
secure the data for transmission and secure communication protocols provide the framework for
communication. Data communication can only be secure when adequate cryptographic methods
are combined with suitable protocols. Using public key cryptography, a party may create a
digitally signed document by encrypting it with his
private key (Diffie and Hellman, 1976).
Polygraphic systems encode a group of plain sequence letters. This scrambles the frequencies
and allows for more than one representation of a plain sequence character. The digraphic system
is the simplest polygraphic system. It uses a 2 x 2 coding matrix to replace pairs of plain
sequence characters. A square matrix of any size may be chosen as a coding matrix. The larger
the coding matrix the more complex the system of cryptography. The examples in this unit use a
trigraphic system. A 3 x 3 matrix is chosen as the coding matrix. The choice of the matrix is
arbitrary. The only constraint is that the coding matrix must have an inverse. It is convenient to
have a prime number of characters in the plain sequence. Therefore, we have added a space and
two punctuation marks to the standard alphabet to create our plain sequence. The plain sequence
and its numerical representations are:
A B C D E F G H I J K L M N O 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
P Q R S T U V W X Y Z ? ! 16 17 18 19 20 21 22 23 24 25 26 27 28 29
Pretty Good Privacy (PGP) provides security for e-mail. This communication security protocol
bears the greatest significance with regard to the level of protection it offers.
There are various communication protocols that were not mentioned in our discussion. This
include the above mentioned PDP and Transport Layer Security (Dierks and Allen, 1999).
References

DIFFIE, W. and HELLMAN, M.E. (1976): New directions in cryptography. IEEE
Transactions on Information Theory, 22(6): 644-654
INFORMATION SECURITY

DIERKS, T. and ALLEN, C. (1999): RFC 2246: The TLS Protocol Version 1.0.
Internet Engineering Task Force.

DENNING, D.E. (1984) Digital signatures with RSA and other public-key
cryptosystems. Communications of the ACM, 27(4): 388-392.