The Complete Run.
The Napkin Index.
Every formula introduced across the 22 stories. The napkin is the artefact. The formula is the lock-in.
| Formula / Rule | What it means | Story |
|---|---|---|
| SLE = AV × EF | Single Loss Expectancy: one incident's cost | 01 — Risk Assessment |
| ALE = SLE × ARO | Annualised Loss Expectancy: yearly cost of a threat | 01 — Risk Assessment |
| ALE(before) − ALE(after) > cost of control | Cost-benefit test: if true, buy the control | 01 — Risk Assessment |
| TCP: SYN → SYN-ACK → ACK | Three-way handshake: reliable connection setup | 04 — TCP, DNS, DHCP |
| DHCP DORA: Discover → Offer → Request → Acknowledge | IP address assignment sequence over UDP | 04 — TCP, DNS, DHCP |
| Digital Signature = Hash + Encrypt(Private Key) | Integrity + non-repudiation in one operation | 11 — Cryptography |
| ALE(before) − ALE(after) > cost → buy it | Risk treatment decision rule | 01 — Risk Assessment |
| RPO = maximum acceptable data loss (backward) | Determines backup frequency | 12 — Resilience & Backups |
| RTO = maximum acceptable downtime (forward) | Determines recovery speed requirement | 12 — Resilience & Backups |
| RAID 5 = stripe + parity (survives 1 drive failure) | Minimum recommended RAID for most use | 12 — Resilience & Backups |
| RAID 6 = double parity (survives 2 drive failures) | Higher tolerance for storage pools | 12 — Resilience & Backups |
| Bell-LaPadula: no read up, no write down | Confidentiality model for MAC | 08 — Access Control |
| Biba: no read down, no write up | Integrity model for MAC (opposite of Bell-LaPadula) | 08 — Access Control |
Test Yourself.
602 SY0-701 practice questions across 5 domains, audited against the official CompTIA objectives. Quick Drill, Mock Exam (90Q · 90 min), Domain Focus, Review Drill (wrong + spaced-repetition due). Plus 5 Performance-Based Question scenarios — the high-value simulation questions worth most of the exam score.
Five Domains.
The foundations. CIA triad, authentication models, cryptography, PKI, access control, and the vocabulary of security controls. Seven stories build this domain — it is the broadest of the five.
The adversary's toolkit. Social engineering, malware taxonomy, application and network attacks, physical security, and the rogues gallery of threat actors. Five stories — dense with exam-critical specifics.
How Cipher Lane is built. RAID, RPO/RTO, backup types, hot/warm/cold sites, DMZ, VLANs, zero trust, and VPN types. Two stories cover the structural layer that holds everything else up.
The shop floor. Ports and protocols, the OSI model, TCP/DNS/DHCP, and incident response. Four stories that cover the operational layer — what you see on the wire and what you do when it goes wrong.