Data

• Information is data that has been organized into meaningful patterns to facilitate decision making.
• A database is an integrated collection of related information about people, places, things, events, etc., which can be accessed by computer programs.
• Data is the raw facts or figures that are collected, processed, stored, retrieved, transmitted, and displayed.
• Data processing involves the manipulation of raw data using computers or other devices to produce useful information.
• Computer hardware refers to physical components such as processors, memory, storage devices, input/output devices, and networking equipment used to build computing systems.
• Data is stored as

  • binary digits or
  • bits
  • these are are in the form of 1s and 0s
• Direct data is data that is collected for a specific purpose or task and is used for that purpose and that purpose only. It is often referred to as ‘original source data’.
• Indirect data is data that is obtained from a third party and used for a different purpose to that which it was originally collected for and which is not necessarily related to the current task.
• Direct data sources

  • Questionnaires
  • Interviews
  • Observation
  • Data logging
• Data logging

  • using a computer and sensors to collect data.
• Indirect data sources

  • Electoral register
  • Businesses collecting data from third parties
• Advantages and disadvantages

  
• advantages and disadvantages pt.2

  
• Quality of information

  • it is sometimes based on the value which the user places on the information collected.
• Factors that affect the quality of information

  • Accuracy
  • Relevance
  • Age
  • Level of detail
  • Completeness of the information
• Encryption

  • the scrambling of data from plaintext to ciphertext
  • its done to avoid falling victim to things such as identity theft, blackmail and cyber-fraud
• how encryption is generally done

  
• Symmetric encryption

  • involves the sending computer, or user, and the receiving computer, or user, having the same key to encrypt and decrypt a message.
• Asymmetric encryption

  • uses two different keys, one public and one private. A public key, which is distributed among many users or computers, is used to encrypt the data. Essentially, this public key is published for anyone to use to encrypt messages. A private key, which is only available to the computers, or users, receiving the message, is used to decrypt the data.
• Encryption protocols

  • IPsec (internet protocol security)-which allows the authentication of computers and encryption of packets of data in order to provide secure encrypted communication between two computers over an internet protocol (IP) network. Used in Virtual Private Networks(VPNs)
  • SSH(secure shell)-used to enable remote logging on to a computer network, securely. SSH is often used to login and perform operations on remote computers, but it can also be used for transferring data from one computer to another.
• Transport Layer Secure/Secure Sockets Layer

  • used when accessing web pages
  • TLS is the better version of SSL, but the terms are used interchangeably
  • USES
  • enable encryption to protect data
  • authentication
  • ensure the integrity of the data to make sure it has not been corrupted or altered.
  • two other purposes are:
  • ensure that a website meets PCI DSS rules.The Payment Card Industry Data Security Standard (PCI DSS) was set up so that company websites could process bank card payments securely and to help reduce card fraud.
  • improve customer trust.
• Many websites use SSL/TLS when encrypting data while it is being sent to and from them. This keeps attackers from accessing that data while it is being transferred.
• • The SSL/TLS protocol verifies the identity of the server. Any website with an HTTPS address uses SSL/TLS. In order to verify the identity of the server, the protocol makes use of digital certificates, which contain such information as the domain name that the certificate is issued for, which organisation, individual or device it was issued to, the certificate authority (CA) that issued it, the CA’s digital signature, and the public key, as well as other items.

  Valid SSL certificates can only be obtained from a CA. CAs

  can be private companies or even governments.
• The use of SSL/TLS in client–server communication

  • Transport layer security (TLS) is used for applications that require data to be securely exchanged over a client–server network, such as web browsing sessions and file transfers.
• • When a browser (client) wants to access a website (server) that is secured by SSL/TLS, the client and the server must carry out an SSL/TLS handshake. A handshake, in IT terms, happens when two devices want to start communicating.
  • This helps the two devices to agree on the rules for communicating
  • Handshaking occurs before the transfer of data can take place.
• Uses of encryption

  • Hard-disk encryption
  • Email encryption
  • Encryption of HTTPS websites
• HTTPS stands for Hypertext Transfer Protocol Secure
• In websites, an RNG based Session key is created during the handshake, encrypted using the public key and sent to the server.The server then decrypts the session key using its private key. All data sent between the two from then on is encrypted using this session key. So, the generation of the session key is done through asymmetric encryption, but symmetric encryption is used to encrypt all further communications. Once the session is finished, the Session key is discarded.
• One disadvantage of encryption is the danger of ransomware. Another is that if anything were to happen to an encrypted hardware, retrieving the data back would be very difficult.