Low Logic
Low Logic is a sanitized challenge note from the local HTB archive, organized for quick review by category, difficulty, evidence flow, and reusable operator
Scenario
Low Logic attack path
Low Logic is a sanitized challenge note from the local HTB archive, organized for quick review by category, difficulty, evidence flow, and reusable operator
Objective
Challenge walkthrough focused on Hardware evidence, validation, and reusable operator lessons.
Walkthrough flow
Artifact inspection
Signal or firmware analysis
Decoded state
Proof captured
Source coverage
High source coverage
Status: complete. This article is generated from 6 sanitized Markdown sources and keeps raw flags, credentials, keys, cookies, and reusable secrets out of the rendered blog.
High confidence: the page is reconstructed from a primary walkthrough plus multiple supporting notes or evidence sources. Treat the chain as source-backed, while still checking the listed source files for sensitive values.
- Hardware/Low-Logic/writeup.md
- htb-challenge/Hardware/Low-Logic/notes.md
- htb-challenge/Hardware/Low-Logic/memory-summary.md
- htb-challenge/Hardware/Low-Logic/hypothesis-board.md
- HTB/_knowledge/exports/ctf-lightrag-latest-203412/documents/challenge__Hardware__Low-Logic__memory-summary.md.cb063b3842.md
- HTB/_knowledge/exports/ctf-lightrag-latest-203412/documents/challenge__Hardware__Low-Logic__notes.md.07648d6a97.md
Technical Walkthrough
Writeup
Challenge
- Name: Low-Logic
- Category: Hardware
- Difficulty: Very Easy
- Mode: file
Summary
The archive was <password redacted>. After validating the password and extracting the files, the chip image showed a simple CMOS circuit equivalent to (in0 AND in1) OR (in2 AND in3). Applying that logic to each CSV row produced a bitstream that decoded directly into the HTB flag.
Artifact Inventory
files/a12c739e-c2c4-4d77-8658-93429e1c29d9.zip— original encrypted challenge archive.analysis/<password redacted>— successful archive access key validation.analysis/extracted/hw_lowlogic/chip.jpg— circuit image.analysis/extracted/hw_lowlogic/input.csv— input rows.analysis/final-flag.txt— recovered flag before harness capture.solve/solve.py— deterministic solver.
Reference analysis/artifact-inventory.json and summarize the relevant files or remote surface.
Analysis
The chip image is a small CMOS logic network that reduces to two AND gates feeding an OR gate, equivalent to (in0 AND in1) OR (in2 AND in3). Each CSV row therefore maps to a single output bit. Concatenating those bits across all rows yields 192 bits, which split cleanly into 24 bytes and decode directly as ASCII.
Solve
The solver reads input.csv, computes one bit per row using (in0 AND in1) OR (in2 AND in3), concatenates the bits, groups them into 8-bit bytes, and decodes the result as ASCII. The decoded string is the HTB flag.
Flag
Raw flag is stored in loot/flag.txt and intentionally not reproduced here.
Lessons
Even Very Easy hardware challenges can hide their first blocker in an encrypted archive rather than the logic itself. Once the artifact is accessible, start by reducing the circuit to a boolean expression and check whether the resulting bitstream decodes directly as text before trying more exotic encodings.
Source-Backed Dossier
The sections below are merged from companion Markdown notes for the same case. They are rendered after sanitization so the article stays precise without publishing raw flags, credentials, or target-specific secrets.
Notes
Scope
- Challenge: Low-Logic
- Category: Hardware
- Difficulty: Very Easy
- Mode: file
- Remote instance: none
- Start time: 2026-06-07T07:39:49Z
- Operator: harness
- State file:
challenge-state.json
Harness Status
- Current phase: see
challenge-state.json - Next allowed actions: see
next-action.json - Raw flags and sensitive material stay in
loot/only. Do not paste them here.
Artifact Inventory
| File | Size | SHA256 | Type | Notes |
|---|---|---|---|---|
files/a12c739e-c2c4-4d77-8658-93429e1c29d9.zip | 39235 | <hash redacted> | Zip archive data, at least v1.0 to extract, compression method=store | zip entries: 3 shown in artifact inventory JSON |
Evidence Ledger
| Time | Action | Output/File | Finding | Confidence | Next |
|---|---|---|---|---|---|
| 2026-06-07T07:39:49Z | harness init | challenge-state.json | Workspace initialized with deterministic state file | High | Inventory artifacts |
| 2026-06-07T07:39:50Z | artifact inventory | analysis/artifact-inventory.json | 1 artifact(s) inventoried | High | Build or update hypotheses |
| 2026-06-07T07:39:50Z | session bootstrap | notes.md | Challenge metadata, scenario, and prior context seeded into workspace | High | Record initial hypothesis and research |
| 2026-06-07T07:39:50Z | hypothesis recorded | hypothesis-board.md | initial triage from supplied challenge metadata | Medium | inventory files / inspect app surface / map routes depending on category |
| 2026-06-07T07:39:50Z | research task | analysis/research/task-20260607T073950137164Z-e3168c06.md | Research task created for advisory investigation | Medium | Record research output |
| 2026-06-07T07:42:29Z | local memory record | analysis/local-memory-records.md | Prior local notes reviewed as fallback/advisory context | Medium | Validate against current evidence |
| 2026-06-07T07:43:30Z | checkpoint recorded | analysis/checkpoint-artifact_inventory-20260607T074330346183Z-f69789ea.md | Checkpoint for <secret redacted> | High | Use checkpoint to drive next decision |
| 2026-06-07T07:44:15Z | checkpoint recorded | analysis/checkpoint-analysis-20260607T074415543884Z-cfdd19ee.md | Checkpoint for ANALYSIS | High | Use checkpoint to drive next decision |
| 2026-06-07T07:47:12Z | checkpoint recorded | analysis/checkpoint-analysis-20260607T074712143478Z-865aa07c.md | Checkpoint for ANALYSIS | High | Use checkpoint to drive next decision |
| 2026-06-07T07:49:52Z | checkpoint recorded | analysis/checkpoint-analysis-20260607T074952079543Z-4dd97a5d.md | Checkpoint for ANALYSIS | High | Use checkpoint to drive next decision |
| 2026-06-07T07:50:46Z | checkpoint recorded | analysis/checkpoint-analysis-20260607T075046967644Z-d7bc851a.md | Checkpoint for ANALYSIS | High | Use checkpoint to drive next decision |
| 2026-06-07T08:12:19Z | checkpoint recorded | analysis/checkpoint-analysis-20260607T081219269646Z-f363b5b2.md | Checkpoint for ANALYSIS | High | Use checkpoint to drive next decision |
| 2026-06-07T08:31:48Z | checkpoint recorded | analysis/checkpoint-analysis-20260607T083148394940Z-3701c286.md | Checkpoint for ANALYSIS | High | Use checkpoint to drive next decision |
| 2026-06-07T08:32:48Z | evaluator | analysis/evaluator-20260607T083248098888Z-30cebc21.md | Proceed | High | Capture the flag through the harness, update notes/writeup, and run the completion gate. |
| 2026-06-07T08:32:48Z | flag capture | loot/flag.txt | HTB-format flag captured; raw value kept in loot only | High | Write solution and run completion gate |
| 2026-06-07T08:32:48Z | Derived CMOS logic and evaluated CSV rows | analysis/extracted/hw_lowlogic/chip.jpg, analysis/extracted/hw_lowlogic/input.csv | The chip implements (in0 AND in1) OR (in2 AND in3); the resulting 192-bit stream decodes directly to an HTB flag string. | High | Capture the flag through the harness and complete the workspace. |
| 2026-06-07T08:33:25Z | completion gate | challenge-state.json | Completion gate passed; state marked COMPLETE | High | Optional sanitized memory summary approval |
Key Findings
-
RAG / Advisory Memory
RAG output is advisory only. Record evaluated retrievals with:
scripts/challenge_harness.py rag-record <workspace> --query "..." --tag MATCHED|PARTIAL|MISSING|<secret redacted>|GENERIC --validation "..."Secrets/Flags
Raw flags and sensitive material stay in loot/ only. Use scripts/challenge_harness.py capture-flag to validate and record flag capture without printing the value.
Scenario
I have this simple chip, I want you to understand how it works and then give me the output.
Operator Question
Analyze the provided hardware challenge artifact, determine how the simple chip/logic works, derive the expected output, and capture the HTB flag.
Memory Summary
Metadata
- Platform: HackTheBox Challenges
- Category: Hardware
- Challenge: Low-Logic
- Difficulty: Very Easy
- Source workspace:
<local workspace>
Validated Solve Chain
Concepts only. Do not include raw flags, reusable credentials, tokens, cookies, private keys, or live secrets.
1.
Reusable Lessons
-
Dead Ends
-
Tool Quirks
-
Evidence Paths
-
Ingestion Decision
- Proposed for LightRAG: yes/no
- Requires user approval before ingestion: yes
Hypothesis Board
Keep no more than 3 active hypotheses on Easy/Medium and 5 on Hard unless the user explicitly asks for breadth.
| Rank | Path | Evidence | Missing Proof | Cheapest Validation | Confidence | Status |
|---|---|---|---|---|---|---|
| 1 | initial triage from supplied challenge metadata | challenge name, category, difficulty, scenario, and remote target were provided by operator | inventory files / inspect app surface / map routes depending on category | Medium | Active |
Closed Branches
| Branch | Evidence Tested | Failure Output | Reason Closed | Revisit Condition |
|---|
Memory Summary
approval_required: true
Sanitized Memory Summary
Metadata
- Platform: HackTheBox Challenges
- Category: Hardware
- Challenge: Low-Logic
- Difficulty: Very Easy
- Source workspace:
<local workspace>
Validated Solve Chain
Concepts only. Do not include raw flags, reusable credentials, tokens, cookies, private keys, or live secrets.
1.
Reusable Lessons
-
Dead Ends
-
Tool Quirks
-
Evidence Paths
-
Ingestion Decision
- Proposed for LightRAG: yes/no
- Requires user approval before ingestion: yes
Notes
Notes
Scope
- Challenge: Low-Logic
- Category: Hardware
- Difficulty: Very Easy
- Mode: file
- Remote instance: none
- Start time: 2026-06-07T07:39:49Z
- Operator: harness
- State file:
challenge-state.json
Harness Status
- Current phase: see
challenge-state.json - Next allowed actions: see
next-action.json - Raw flags and sensitive material stay in
loot/only. Do not paste them here.
Artifact Inventory
| File | Size | SHA256 | Type | Notes |
|---|---|---|---|---|
files/a12c739e-c2c4-4d77-8658-93429e1c29d9.zip | 39235 | <hash redacted> | Zip archive data, at least v1.0 to extract, compression method=store | zip entries: 3 shown in artifact inventory JSON |
Evidence Ledger
| Time | Action | Output/File | Finding | Confidence | Next |
|---|---|---|---|---|---|
| 2026-06-07T07:39:49Z | harness init | challenge-state.json | Workspace initialized with deterministic state file | High | Inventory artifacts |
| 2026-06-07T07:39:50Z | artifact inventory | analysis/artifact-inventory.json | 1 artifact(s) inventoried | High | Build or update hypotheses |
| 2026-06-07T07:39:50Z | session bootstrap | notes.md | Challenge metadata, scenario, and prior context seeded into workspace | High | Record initial hypothesis and research |
| 2026-06-07T07:39:50Z | hypothesis recorded | hypothesis-board.md | initial triage from supplied challenge metadata | Medium | inventory files / inspect app surface / map routes depending on category |
| 2026-06-07T07:39:50Z | research task | analysis/research/task-20260607T073950137164Z-e3168c06.md | Research task created for advisory investigation | Medium | Record research output |
| 2026-06-07T07:42:29Z | local memory record | analysis/local-memory-records.md | Prior local notes reviewed as fallback/advisory context | Medium | Validate against current evidence |
| 2026-06-07T07:43:30Z | checkpoint recorded | analysis/checkpoint-artifact_inventory-20260607T074330346183Z-f69789ea.md | Checkpoint for <secret redacted> | High | Use checkpoint to drive next decision |
| 2026-06-07T07:44:15Z | checkpoint recorded | analysis/checkpoint-analysis-20260607T074415543884Z-cfdd19ee.md | Checkpoint for ANALYSIS | High | Use checkpoint to drive next decision |
| 2026-06-07T07:47:12Z | checkpoint recorded | analysis/checkpoint-analysis-20260607T074712143478Z-865aa07c.md | Checkpoint for ANALYSIS | High | Use checkpoint to drive next decision |
| 2026-06-07T07:49:52Z | checkpoint recorded | analysis/checkpoint-analysis-20260607T074952079543Z-4dd97a5d.md | Checkpoint for ANALYSIS | High | Use checkpoint to drive next decision |
| 2026-06-07T07:50:46Z | checkpoint recorded | analysis/checkpoint-analysis-20260607T075046967644Z-d7bc851a.md | Checkpoint for ANALYSIS | High | Use checkpoint to drive next decision |
| 2026-06-07T08:12:19Z | checkpoint recorded | analysis/checkpoint-analysis-20260607T081219269646Z-f363b5b2.md | Checkpoint for ANALYSIS | High | Use checkpoint to drive next decision |
| 2026-06-07T08:31:48Z | checkpoint recorded | analysis/checkpoint-analysis-20260607T083148394940Z-3701c286.md | Checkpoint for ANALYSIS | High | Use checkpoint to drive next decision |
| 2026-06-07T08: <REDACTED>, update notes/writeup, and run the completion gate. | |||||
| 2026-06-07T08: <REDACTED> | |||||
2026-06-07T08: <REDACTED>, analysis/extracted/hw_lowlogic/input.csv | The chip implements (in0 AND in1) OR (in2 AND in3); the resulting 192-bit stream decodes directly to an HTB flag string. | High | Capture the flag through the harness and complete the workspace. | ||
| 2026-06-07T08:33:25Z | completion gate | challenge-state.json | Completion gate passed; state marked COMPLETE | High | Optional sanitized memory summary approval |
Key Findings
-
RAG / Advisory Memory
RAG output is advisory only. Record evaluated retrievals with:
scripts/challenge_harness.py rag-record <workspace> --query "..." --tag MATCHED|PARTIAL|MISSING|<secret redacted>|GENERIC --validation "..."Secrets/Flags
Raw flags and sensitive material stay in loot/ only. Use scripts/challenge_harness.py capture-flag to validate and record flag capture without printing the value.
Scenario
I have this simple chip, I want you to understand how it works and then give me the output.
Operator Question
Analyze the provided hardware challenge artifact, determine how the simple chip/logic works, derive the expected output, and capture the HTB flag.
Technical analogy
How to remember this solve
Think of the hardware challenge like following copper tracks on a circuit board. The useful clue is usually where signals enter, where they are transformed, and which debug or storage path exposes hidden state.
For Low Logic, keep the mental model simple: identify the trusted assumption, prove it with the smallest safe test, then automate or repeat only the part that directly leads to the flag.