Network Security. File Access Permission. Firewall
The network security (or information security) is to provide protection to the computer system from the hackers (intruders). Network security focuses on protecting data resources from external attack and also from simple mistakes made by the users withinan organization.
Network security also designs computer network infrastructure, policies and rules adopted by the network administrator to protect the network and the
network-shareable resources from.
The security system also monitor consistently and continuously the effectiveness of all the security measure. In a computer network or even in the internet, some files or documents are made shareable and some are made public. The protected sharable files and documents are shared among few users or even by a group having the access rights. Access rights are generally decided and given by the owner of the file or the network administrator. Thus the three types of users can access a file or a folder i.e. Owner, user having access rights, or all other users.
A firewall is a technique used in a secured computer system or network to block unauthorized access and allow only the authorized user. Firewalls can be implemented in either hardware or software, or a combination of both. It is a device or set of devices or software running on a computer, which is configured to permit or deny computer
applications and set of other software based upon a set of rules and other criteria designed by the network administrator. It also inspects network traffic passing through
it, and denies or permits passage. It is normally placed between a protected network (usually a LAN) and an unprotected network (usually WAN or Internet) and acts like a gate to protect all resources to ensure that nothing goes out without permission and nothing unwanted comes in into the system.
Firewalls are frequently used to prevent unauthorized Internet users from accessing private networks connected to the Internet, especially intranets. All messages entering or leaving the intranet pass through the firewall, which examines each message and blocks those that do not meet the specified security criteria.
A digital certificate (also known as a public key certificate or identity certificate) is an electronic document which uses a digital signature to bind together a public key or password required for decode and encoded document with an authentic identity such as the name of a person or an organization, their phone numbers or address, and so forth. The certificate can be used to verify that a public key belongs to an authorized individual or organization.
As remarked in the beginning of this chapter, Cyber crime (or Computer crime) refers to any crime wherein the computer is either a tool or a target or both.
Some forms of the Cyber Crime are:
Creating and distributing Spam Mails
Fraud through Internet or intranet
Sending Obscene or Offensive messages
Creating Websites with Obscene or Offensive content