Skip to content
academia.sh
tr
Log in

Course Beginner

Introduction to Cybersecurity

Published Updated

By the end of this course

Start course

01

Security Concepts

Establishing security's units of measure: the confidentiality, integrity, and availability axes overlapping on the same asset, the asset, threat, and vulnerability terms separated into distinct lists in the same inventory, risk calculated as the composition of probability and impact and turned into a ranking, the chain from vulnerability to impact broken into steps, and attack surface reduced to a countable number of paths in an access graph.

  1. 01 Confidentiality, Integrity and Availability The three axes overlapping on the same asset: in a model with eight assets and six decisions, 27 (item, axis) pairs rise while 22 fall; the confidentiality total climbs from 34 to 41, integrity from 44 to 63, and availability from 47 to 51; a decision with zero net effect raises availability by nine points while lowering confidentiality by six; on key loss the availability total drops from 51 to 24 and four of eight assets are zeroed; and through all of it the average score falls only from 6.5 to 5.3.
  2. 02 Asset, Threat and Vulnerability Separating three terms into the same inventory: the cartesian product of 8 assets, 6 threats, and 12 vulnerabilities is 576, while the valid-triple count drops to 19, or 3.3%; two assets each carrying two vulnerabilities produce 1 and 4 triples; a vulnerability no threat can reach carries zero triples; two threats carrying the same five triples touch 4 and 5 separate assets; closing five of twelve vulnerabilities closes 12 of the 19 triples; and narrowing an asset's zone closes 3, 2, 1, or no triples at all.
  3. 03 Risk Definition Calculating risk as the composition of probability and impact: in a 12-item list the total expected loss comes to 176.05 fictional units; banded scoring changes the rank of 9 items in the same list, carries the largest shift to 6 positions, and leaves only 2 of the top five shared; for threshold scoring those numbers are 7, 4, and 4; a four-item budget closes 77.00, 67.60, and 71.40 units across the three scoring schemes; and two items carrying the same 18.00 expected loss produce 4.0 and 0.3 events over ten years.
  4. 04 Exploit and Payload Breaking the chain from vulnerability to impact into steps: 5 exploits and 4 payloads produce 12 valid chains; chain length ranges from 2 to 7 and totals 53 steps; breaking a single step cuts at most 8 chains; blocking a payload cuts at most 5 chains and blocking an exploit at most 4; the same break leaves 0 completed steps at access and 41 at impact; even when all six middle steps are broken, 1 of 12 chains still stands; and that single chain carries 25.7% of the total probability mass.
  5. 05 Attack Surface Converting surface into a countable unit: in a 13-node, 21-edge access graph, four entry points to two targets produce 35 separate paths; the entry point carrying only 1.4% of total legitimate work opens 37.1% of the paths; a single edge can close 14 paths; one edge stops 4 legitimate work items and closes no path at all; greedy narrowing by ratio zeroes the paths at a cost of 31 legitimate work items, and closing all entry points reaches the same result at a cost of 27.

02

Defense Principles

Six defense principles are measured on the same path set: the path defense in depth closes layer by layer, the path least privilege closes through narrowing and the legitimate work it stops, the item a compartment reaches when it falls under compartmentalization, the path count and extra step per request that change when location-based trust is removed, the path that opens when authentication and authorization are collapsed into the wrong layer, and the path secure defaults opens when one item is forgotten.

  1. 01 Defense in Depth Five defense layers are added in sequence over the same access graph: the new path each layer closes, the path left over, the legitimate flow needing an exception, and the managed item count are all counted. A layer that closes no new path is found, and how order changes the distribution of closures is shown.
  2. 02 Least Privilege Every step of the same access graph is tied to a permission item, and the path it opens is counted side by side with the daily legitimate request it carries. Removing items that carry no legitimate traffic is measured as cost-free, then the stopped-request-per-path threshold is swept to find where narrowing turns expensive.
  3. 03 Isolation The same network is built with seven separate compartment schemes, and the reached item is counted when a node falls. Gate count, the daily legitimate request passing through the gate, and how much the compartment count narrows the reached asset are all measured together; the location of the boundary is shown to be more decisive than the compartment count.
  4. 04 Zero Trust As location-based trust is removed, verification scope is widened in five steps, and at each step the path count, daily verification, and extra step per request are counted together. The reason the paths left open under zero trust stay open is found, and how many internal flows carrying identity end to end would change is measured.
  5. 05 Authentication and Authorization Distinction Two controls are placed in separate scopes over the same step set and measured against two separate requests: a forged-identity request and a verified-but-unauthorized request. How many paths putting authentication at every step closes against a verified-but-unauthorized request, and how many paths asking authorization only at the data layer opens, are counted.
  6. 06 Secure Defaults What happens when one of twenty-two configuration items is forgotten is counted separately under two defaults: the path opened under an open default, the daily work stopped under a closed default. The count of forgotten items is swept, and resilience to misconfiguration is measured by comparing the visibility rate of the two error types.

03

Field and Roles

Who does the measuring and within what boundary it can be done: separating what blue, red, and purple teams each see within the same set of paths, counting the information gap, splitting security roles by responsibility item, measuring the item left unowned and the item claimed twice, establishing authorization, scope, and responsibility as countable items, and comparing the skill set professional competency paths measure.

  1. 01 Blue, Red, and Purple Teams How three teams differ over the same set of paths: in a 30-path access graph, the 11 paths the defense knows, the 15 the attacking side finds, the 8 items where the two do not overlap, and the 13 paths neither sees; how purple work drives the information gap from 6 down to 0, how the closed paths climb from 17 to 22 while the legitimate requests they stop fall from 2,764 to 2,037, and how 8 out-of-scope paths remain.
  2. 02 Security Roles Splitting roles by responsibility item: of 9 item types and 3 duties across 27 cells, 15 have a single owner, 7 are unowned, 3 have two owners, and 2 sit past the boundary; the unowned item forces 12 paths to close from a more costly step, 2 paths never close, 15 closures require two approvals, and writing the boundary drops stopped legitimate requests from 2,321 to 2,135.
  3. 03 Legal Framework and Ethics Establishing authorization, scope, and responsibility as countable items: in an 18-asset inventory, four scope wordings cover 8, 13, 17, and 15 assets; the disputed item count is 0, 6, 9, and 0; in the wording written as a named list, 9 neighboring assets sit in the same segment; two assets require separate written permission each; and the undisputedly testable path count is 8, 5, 8, and 22.
  4. 04 Professional Competency Paths Separating competency paths by what they measure: in a 15-item competency set, multiple-choice certification measures 2 items, the practical exam 9, and the lab environment 6; the two exam formats agree on 2 items and diverge on 7; the three paths together measure 10 items; and the 5 items none of them measure carry 39.2% of the total path load.

Final exam

Introduction to Cybersecurity — Final Exam

In preparation

This course's question bank is not complete yet. The exam opens here automatically once enough questions are added.

Start typing to search.

↑↓ ↵ Esc navigate · open · close