Encryption:

Computer network have lots of vulnerabilities and threads, a hacker can log into computer
remotely and destroy the information and malicious program can wipe out data on hundreds
of computer causing huge loses. That’s why Computer system needs to be encrypted by
encrypted protocol to protect from unauthorised access. The selection of encryption key and
protocol has criteria’s by which a computer system can be protected properly. These are the
key criteria describe bellow.

Encryption key criteria:
1) Confidentiality: confidentiality or privacy keeping data, information and massage secret
from all but those who are authorized to have it. Confidentiality is a term identical with
secrecy and privacy. There are many approaches that are providing confidentiality, physical
protection to mathematical algorithms which data making no sense.
2) Data integrity: Data integrity ensures the information has not been altered, damaged or by
unauthorized or unidentified and unknown access. This is a service which addresses the
illegal modification of data. To assure data integrity is done by detecting data manipulation
by unauthorized accesses. There are types of data manipulation such as insertion, deletion,
and substitution.
3) Authenticity: “Entity authentication or identification corroboration of the identity of an
entity (e.g., a person, a computer terminal, a credit card, etc.)” (Alfred J., 1996)
Authentication is a service related to recognition or identification. That is means; it applies in
both area of authentication. When entering into a communication should identify each other
and Information passes over a channel should be authenticated as to origin, date of origin,
data content, time sent etc. Cryptography is usually divided into two categories; entity
authentication and data origin authentication. Data origin authentication unconditionally
provides data integrity.
4) Non-repudiation: Non-repudiation prevents the rejection of earlier commitments or
procedures. When disagreement occurs due to an entity denying actions were taken to resolve
the state is necessary. “For example, one entity may authorize the purchase of property by
another entity and later deny such authorization was granted. A procedure involving a
trusted third party is needed to resolve the dispute” (Alfred J., 1996)
Key criteria of cryptography are to sufficiently address these four areas in both theory and
practice for prevention of malicious activities and detection of cheating.