Latest Entries »

There are many ways in which the Internet has affected families, here are just some of them:

  • You can now keep in touch with family members who live around the world using social networking sites or video conferencing as forms of communication.
  • It is much easier to send and receive multimedia such as videos and photos of family members.
  • In most cases, there will be an increase in computer usage in a household.
  • However, there will be more Internet Safety issues which the families have to deal with such as hacking, security breaches and peadophilia.
  • The Internet could also help with homework or study which the family have to do.

The Internet has also affected employment, here are a few ways in which this has happened:

  • Companies now have the ability to create e-commerce websites in order to sell their products online which has many advantages and disadvantages.
  • Home/Teleworking can be used a lot more by businesses as employees can use the Internet to communicate with colleagues as well as using video conferencing to participate in meetings, for example.
  • The company can use cloud storage instead of using physical storage that would take up space and possibly cost more money; however there is more chance of cloud storage being corrupted.
  • The Internet makes it easier for the employer to monitor employee’s social life, as well as making it easier for the company to monitor competitor’s progress.


RSA – A system that uses two keys – a public key known to everyone and a private/secret key known only to the recipient of the message. An important element to the public key system is that the public and private keys are related in such a way that only the public key can be used to encrypt messages and only the corresponding private key can be used to decrypt them. Moreover, it is virtually impossible to deduce the private key if you know the public key.

Pretty Good Privacy (PGP) – PGP is based on the asymmetric method which uses the two keys. The difference between this system and the RSA system is that it uses both symmetric and asymmetric methods.

Asymmetric and Symmetric Encryption – Symmetric encryption is an encryption system in which the sender and receiver of a message share a single, common key that is used to encrypt and decrypt the message. Contrast this with asymmetric encryption which utilizes two keys – a public key to encrypt messages and a private key to decrypt them.

Symmetric-key systems are simpler and faster, but their main drawback is that the two parties must somehow exchange the key in a secure way. Public-key encryption avoids this problem because the public key can be distributed in a non-secure way, and the private key is never transmitted.

Cipher Text – This is unreadbale text, and can only be read when it has been decrypted with a key.


Nominet is the official body who is responsible for the administration of almost all of the domain’s which end in ‘.uk’. Unlike similar organisations in other countries, Nominet does not sell or register domain names, they just give advice to people who need help with maintaining and protecting their domain names.

Class B

A Class B network was a network in which all addresses had the two most-significant bits set to 1 and 0. For these networks, the network address was given by the next 14 bits of the address, therefore leaving 16 bits for numbering host on the network for a total of 65536 addresses per network.

Class C

Class C was defined with the 3 high-order bits set to 1, 1, and 0, and designating the next 21 bits to number the networks, leaving each network with 256 local addresses.

Subnet Masking

Subnetting enables the network administrator to further divide the host part of the address into two or more subnets. In this case, a part of the host address is reserved to identify the particular subnet.
So a subnet mask is used to determine what subnet an IP address belongs to. An IP address has two components, the network address and the host address. For example, consider the IP address Assuming this is part of a Class B network, the first two numbers (150.215) represent the Class B network address, and the second two numbers (017.009) identify a particular host on this network.

Security Strategy

When implementing a security strategy, an organisation must consider many things including:

  • Access Rights – which level of access does each employee get. For example, high access (executing files) or low access (read).
  • Should passwords be used to access the data. For example, upper or lower case/numbers/symbols.
  • Should encryption be used to secure the data.

The company can use systems like firewall to help prevent the data being accessed by unauthorised people. This works by being installed into either hardware or software; then all messages entering or leaving the private network are passed through the firewall, and block all that do not meet the specified security criteria.

Four Functions of an OIS

Gathering Data

This involves using, for example, bar codes or mark sense readers to collect the data.

Storing Information

CD-ROM’s or memory sticks can be used to store the information, for example.

Processing Information

After the information is stored, it can be searched, sorted, aggregated or calculations can be performed with it to suit the user’s needs.

Outputting Information

This is the fourth and final function of an OIS, and this involves using databases and spreadsheets to allow the users to see the information.

Gathering Data

  • Shop (item details) – Bar code
  • Shop (payment) – Chip and pin
  • Shop (lottery ticket) – Mark sense reader
  • Lawyer (legal  documents) – Scanner
  • Mail Order Companies (telephone) – Keyboard
  • Mail Order Companies (online) – Keyboard
  • Bank (payment details) – MICR

Bar Codes = A barcode is an optical machine-readable representation of data relating to the object to which it is attached.
Optical Mark Recognition = This is the process of capturing human-marked data from document forms such as surveys and tests.
Optical Characer RecognitionThis is the mechanical or electronic conversion of scanned images of handwritten, typewritten or printed text into machine-encoded text.
PaypalThis is a global e-commerce business allowing payments and money transfers to be made through the Internet. Online money transfers serve as electronic alternatives to paying with traditional paper methods, such as checks and money orders.
Magnetic Strip – This is a type of card capable of storing data by modifying the magnetism of tiny iron-based magnetic particles on a band of magnetic material on the card.
Magnetic Ink Character RecognitionThis is a character recognition technology used primarily by the banking industry to facilitate the processing of cheques and makes up the routing number and account number at the bottom of a cheque.


A script is a list of commands that can be executed by a program. Scripts can be used to extend the functionality of a database management system. A scripting language is easier to learn and use than a full-blown programming language. Scripting languages only let the user select code which won’t crash the program.

An example of my scripting language was creating a button in a music database, which took the user to a separate website which was related to the database itself.

An SQL has 3 parts:

  1. A data definition language which allows the creation, modification and deletion of tables and fields.
  2. A data manipulation language which allows data to be entered, modified, deleted and read from a database.
  3. A data control language which allows alternate views of the data in the table to be created.

SQL Keywords

SELECT – This calls upon a specific attribute from the table.
FROM – This calls upon a specific table in which the attribute should be taken from.
WHERE – This is what decides which predicates are returned to the user from the specific attribute.
DELETE – Any rows which match the ‘WHERE’ condition will be deleted.
ORDER BY – This allows the user to sort the returned values.
UPDATE – This allows the user to change one or more records in a table at the same time.
INSERT – This allows the user to add one or more records into the table.
HAVING – This returns fields which reach a certain numeric value, such as ‘>1000’ or ‘<=750’.


Un-normalised Form

  • List all the attributes, only showing any attribute once.
  • Identify primary key from list of candidate keys.
  • Identify repeating groups of attributes.
  • Name the relation.

First Normalised Form

  • Remove repeating groups to new entity.
  • Identify primary key of new entity.
  • Create foreign key in new entity to relate to original entity.

Second Normalised Form

  • Look at tables with a composite key.
  • Review each non-key attribute to identify whether the attribute is dependent on part of the key or all of the key.
  • Remove any partial key and dependants to a new table.

Third Normalised Form

  • Identify dependencies between non-key attribute within each table.
  • Remove them to a new table.
  • Decide on a primary key.
  • This primary key becomes the foreign key in the original table.