Cybersecurity is the practice of protecting computer systems, networks and data from unauthorised access, damage or disruption.
The three basic goals
- Confidentiality — information is available only to those permitted to see it.
- Integrity — data cannot be altered without detection.
- Availability — systems work when they are needed.
Every security decision trades one of these against convenience, cost or the others.
Common attack types
- Phishing — deceptive messages that persuade a person to reveal credentials. Still the most successful entry method.
- Malware — malicious software, including ransomware that encrypts files and demands payment.
- Credential stuffing — reusing passwords leaked from one service to break into another.
- SQL injection — inserting database commands through an input field.
- Denial of service — overwhelming a system so legitimate users cannot reach it.
Defence in depth
No single control is sufficient. Effective protection layers several:
- multi-factor authentication;
- least privilege — each account has only the access it needs;
- patching known vulnerabilities promptly;
- network segmentation;
- logging and monitoring;
- tested backups kept offline.
The human factor
Most successful intrusions involve a person, not a broken algorithm: a reused password, an unexpected attachment, an urgent request that bypasses procedure. Training and clear processes therefore matter as much as technical controls.
Backups
A backup that has never been restored is not a backup. Recovery should be tested on a schedule, and at least one copy should be isolated from the network so that ransomware cannot reach it.