Security, privacy and data integrity
Security - methods taken to prevent unauthorised access to data and to recover data if lost or corrupted.
- Software Security - the collection of methods used to protect computer programs and sensitive information they handle against malicious attacks.
- Hardware Security - vulnerability protection that comes in the form of a physical device rather than the software.
Privacy - freedom from unauthorised intrusion.
Data Integrity - the accuracy, completeness and consistency of data.
- TO MAINTAIN the accuracy 准确性, completion 完整性, and consistence 一致性 of data
- DURING: data entry (visual check, double entry) and data transfer (parity check, checksum)
Authentication 认证 - a way of proving somebody or something is who or what they claim to be.
Access Control & Access Right - use of access level to ensure only authorised users can gain access to certain data.
Encryption - the use of encryption keys to make data meaningless without the correct decryption key.
Firewall - software or hardware that sits between a computer and external network that monitors and filters all incoming and outgoing activities.
Password - a sequence of characters required for access to a computer device or digital device.
Digital Signatures - a way of validating the authenticity of a digital document and identifying the sender.
Biometrics - use biological features to identify a person, e.g. fingerprints and iris
Malware (virus, spyware…) - malicious software that seeks to damage or gain unauthorised access to a computer system.
- Risk restriction: Ensure anti-virus and anti-spyware software is installed, regularly updated and run.
Phishing - legitimate-looking emails designed to trick a recipient into giving their personal data to the sender of the email.
- Risk restriction: Ignore suspicious mails and ensure firewall criteria include SPAM filters, blacklist, etc.
Pharming - redirects a user to a fake website in order to illegally obtain personal data about the user.
- Risk restriction: use a reliable ISP; check that links are genuine 真实的 and ensure https is present in the URL
Validation — method used to ensure entered data is reasonable and meets certain input criteria.
- range check
- format check
- length check
- presence check
- existence check
- limit check
- check digit
Verification — method used to ensure data is correct by using double entry or visual checks.
- during data entry: visual check, double entry
- during data transfer: parity check, checksum
Digital Signature
Without a digital signature, there is no way to verify the sender of the data.
Digital signatures ensure authentication and non-repudiation.
How it works:
- The sender hashes the document → produce a digest.
- The sender encrypts (use private key) the digest to create the digital signature.
- The message and the signature are sent to the receiver.
- The receiver decrypts (use public key) the signature → reproduce the digest.
- The receiver uses the same hashing algorithm on the document received to produce a second digest.
- The receiver compares the two digests.
- If same → the document is authentic.
