STUDY GUIDE · GKU 2

Data security: cryptography, forensics and databases study guide (Cybersecurity)

Data is the asset most attacks are after, and this unit is the three ways a defender protects it. Cryptography turns readable data into data that only a key holder can read, detects changes, proves origin and supports non-repudiation; its failures — a bad mode, a reused nonce, a weak parameter, a stolen key — are more common than broken mathematics. Digital forensics is the disciplined recovery of what happened from devices and logs, in an order that does not destroy the evidence and in a form a Saudi court will accept. Database security is the last line: the DBMS itself decides who may read which row, how queries are built, what is stored in a password column and how a stolen backup is made useless. Each section opens with a quick-revision card, and the worked examples run from easy to exam level. The cryptographic arithmetic uses deliberately small numbers so that every step can be checked by hand; the real systems named alongside it use keys hundreds of times longer.