Access levels

Anti-virus

Asymmetric key encryption

Authentication

Backdoor

Biometric enrolment

Biometric template

Biometrics

Botnet

Brute force attack

CAPTCHA

Certificate Authority

Ciphertext

Computer Misuse Act

Cracking

DDoS

Denial of service attack

Dictionary attack

Digital signatures

Distributed Denial of Service
attack

DNS poisoning

DoS

Drive-by download

Encryption

Encryption key

EV SSL

False negative

False positive

Full disk encryption

Hacking

Home directory

HTTPS

Identity theft

Key escrow

Key logger

Key pair

Macro virus

Malware

Multi-factor authentication

One time password

Packet sniffer

Passphrase

Password

Pharming

Phishing

Physical security

Plaintext

Private key

Public key

Public key encryption

Root user

Rootkit

Secret key encryption

Secure Socket Layer

Security token

Security update

Smishing

Social engineering

Spam

Spam bot

Spam filters

Spyware

SSL

Symmetric key encryption

System administrator

TLS

Transport Layer Security

Trojan horse

Unauthorised access

Virus

Virus definition file

Vishing

Vulnerability scanner

Web bug

WEP