scenarios; that capacity is reliant on the existence of a comprehensive disaster
recovery plan (DRP). Safeguards against data loss or interruptions in
connections must include unpredictable events such as natural disasters and fire.
To prevent data loss from such occurrences, a backup copy may be stored in a
geographically-isolated location, perhaps even in a fireproof, waterproof safe.
Extra security equipment or software such as firewalls and proxy servers can
guard against downtime and unreachable data due to malicious actions such as
denial-of-service (DoS) attacks and network intrusions.
2. Explain Access Control Matrix.
computer science, an Access Control Matrix or Access
Matrix is an abstract, formal security model of protection state in
computer systems, that characterizes the rights of each subject with
respect to every object in the system. It was first introduced by Butler
W. Lampson in 1971. An access matrix can be envisioned as a
rectangular array of cells, with one row per subject and one column
per object. The entry in a cell – that is, the entry for a particular
subject-object pair – indicates the access mode that the subject is
permitted to exercise on the object. Each column is equivalent to
an access control list for the object; and each row is equivalent to
an access profile for the subject.
According to the model, the protection state of a computer system can be
abstracted as a set of objects, that is the set of entities that needs to be protected
(e.g. processes, files, memory pages) and a set of subjects, that consists of all
active entities (e.g. users, processes). Further there exists a set of rights of the
form, where , and. A right thereby specifies the kind of access a subject is
allowed to process object.
3. Explain Symmetric Key Distribution, Public Key Cryptography and Public Key Distribution.
Ans. Symmetric encryption is a form of computerized cryptography using a singular
encryption key to guise an electronic message. Its data conversion uses a
mathematical algorithm along with a secret key, which results in the inability to make
sense out of a message. Symmetric encrpytion is a two-way algorithm because the
mathematical algorithm is reversed when decrypting the message along with using
the same secret key.
Symmetric encryption is also known as private-key encryption and secure-key
encryption. The two types of symmetric encryptions are done using block and stream
algorithms. Block algorithms are applied to blocks of electronic data. Specified set