Measures to Combat Computer Crimes
- Install strong doors and locks to computer rooms to prevent equipment theft.
- Use access control mechanisms to ensure confidentiality, integrity and availability.
- Encrypt confidential data stored on computers or transmitted over networks.
- Install anti-virus software and update it regularly.
- Install intrusion detection systems to help detect unauthorized access.
- Install firewalls to prevent unauthorized access to local networks.
Computer Security
Computer security is the process of preventing and detecting the unauthorized use of computer systems, whether accidental or intentional. Prevention stops unauthorized users accessing the system; detection determines whether someone attempted to break in, whether they succeeded, and what they did. Computer security has three main goals, summarized by the acronym CIA: Confidentiality (information not accessed by unauthorized persons), Integrity (information not altered undetectably by unauthorized persons), and Availability (the system is running and reachable).
a. Authentication
The process of determining if someone is who they claim to be, using three basic strategies: something the user knows (a password), something the user has (a smartcard), or something the user is (biometrics).
- Passwords: guidelines for a secure password include keeping it secret, changing it regularly, making it at least eight characters, avoiding proper words or phrases, mixing upper/lower case letters and numbers, using a different password per system, and limiting login attempts.
- Smart Card: a small card holding user authentication information, read by a card reader – cards can be stolen, so less reliable than biometrics.
- Biometric: uses measurable biological characteristics – fingerprints, eye retinas, iris patterns, facial patterns, voice patterns or hand measurements – the safest authentication technique.
b. Encryption
The process of transforming data into a form unreadable by anyone except the intended recipient, using an algorithm. The original message is plaintext, the algorithm is a cipher, and the encrypted text is ciphertext; reading it requires a secret key to decrypt it. The reverse process is called decryption.
c. Firewall
A computer program or device designed to prevent unauthorized access to or from a private network, implemented in hardware, software, or both. All messages entering or leaving the network pass through the firewall, which examines and blocks anything that doesn’t meet the specified security criteria.
d. Intrusion Detection
The art and science of sensing when a system or network is being used inappropriately or without authorization. An Intrusion Detection System (IDS) monitors system and network resources and activities, notifying the authorities when it identifies a possible intrusion.
e. Digital Signatures
A way to ensure an electronic document is authentic – that you know who created it and it has not been altered since. It is a computed digest of the text, encrypted and sent with the message; the recipient decrypts the signature and compares it with the received text to confirm it is intact.
Physical Security
Tangible defenses that protect a facility, equipment and information from theft, tampering, misuse and natural disasters:
- Thieves: keep computers in rooms with locks and alarms.
- Fire and smoke: install and periodically check smoke detectors and fire extinguishers.
- Climate: keep rooms at 10-26°C with 20-80% humidity, and install alarms for out-of-range conditions.
- Water: let wet equipment dry before turning it on, and install a water sensor where appropriate.
- Electricity: install an uninterruptible power supply (UPS) to absorb surges and provide backup power during a blackout, on a well-grounded electrical system.
