BA-10 · LESSON 07

Protocol attack surfaces

KEY DEFINITIONS

Terms used in this lesson

Oracle: A system that reports outside information, such as a market price, for use by a protocol.
API: Application programming interface: a defined way for one program to request data or actions from another.
BTC: The common market ticker for bitcoin.
USD: United States dollar, the reference currency in a BTC/USD price.
Collateral: An asset pledged against a debt; it can be used to cover the debt if agreed conditions are breached.
Identifier: Identifier: a value used to distinguish one request, object, or participant from another.

Parsing, consensus divergence, nonce reuse, oracle manipulation, key compromise, and economic exploits require layered controls.

55 min Difficulty 3/5 Not started

VISUAL MODEL

See the whole mechanism before going step by step

Use the diagrams to orient yourself. Then the guided explanation below teaches every part in depth.

4 explanatory views

CONCEPT-SPECIFIC MAP · privacy boundaryObservable evidence creates inferences, not automatic proofSelect any state to inspect its exact role.

RELATIONSHIP MAPCompeting paths and resolution

01
OBSERVABLEAmount, script, timing
Chain and network observers see different subsets of transaction and propagation data.
02
HEURISTICProbabilistic link
Wallet patterns can support a guess but do not prove a real-world identity.
03
RISKProtocol attack surfaces
The Protocol attack surfaces lesson identifies which evidence or failure is in scope.
04
CONTROLReduce or separate evidence
Address discipline, coin selection, local verification, and routing choices change exposure.
05
RESIDUALExplicit remaining observer
Every mitigation leaves assumptions and observers that must be named honestly.

Rule shown: Privacy improves by reducing linkable evidence and separating observers, while preserving verifiable spending rules.

STAGE 1 OF 5OBSERVABLE: Amount, script, timing

Chain and network observers see different subsets of transaction and propagation data.

Governing relationship: Privacy improves by reducing linkable evidence and separating observers, while preserving verifiable spending rules. Complete path: 1. OBSERVABLE, Amount, script, timing. Chain and network observers see different subsets of transaction and propagation data. 2. HEURISTIC, Probabilistic link. Wallet patterns can support a guess but do not prove a real-world identity. 3. RISK, Protocol attack surfaces. The Protocol attack surfaces lesson identifies which evidence or failure is in scope. 4. CONTROL, Reduce or separate evidence. Address discipline, coin selection, local verification, and routing choices change exposure. 5. RESIDUAL, Explicit remaining observer. Every mitigation leaves assumptions and observers that must be named honestly.

1. State transitionWhat exists, what changes, and what results

BEFORE

Protocol accepts a signed BTC/USD report to change collateral state.

MECHANISM

List funds, keys, state, availability, privacy, and governance decisions plus every component that can change them.

AFTER

One cryptographic check rarely covers source truth, freshness, software correctness, liveness, and economic safety at once.

Text equivalent: Starting from Protocol accepts a signed BTC/USD report to change collateral state. The mechanism begins when List funds, keys, state, availability, privacy, and governance decisions plus every component that can change them. The resulting lesson is One cryptographic check rarely covers source truth, freshness, software correctness, liveness, and economic safety at once.

2. Mechanism pathSelect a stage to inspect its job

STAGE 1 OF 5

Inventory assets and boundaries

List funds, keys, state, availability, privacy, and governance decisions plus every component that can change them.

Complete path: 1. Inventory assets and boundaries: List funds, keys, state, availability, privacy, and governance decisions plus every component that can change them. 2. Trace untrusted inputs: Network bytes, files, application programming interfaces (APIs), oracle reports, transactions, signatures, configuration, and user fields pass through parsers and validation. 3. Model failure classes: Separate cryptographic break, implementation bug, consensus split, authorization failure, data manipulation, liveness loss, and incentive exploit. 4. Assign independent controls: Use strict parsing, domain separation, policy checks, limits, quorum, monitoring, circuit breakers, and reconciliation where they address named paths. 5. Test adversarially: Fuzz malformed inputs, replay messages, reorder events, corrupt dependencies, remove operators, move prices, and exercise rollback under controlled conditions.

3. Rule and failure boundaryWhat accepts the result and where it can stop

ACCEPTED PATH

Every threat case names asset, boundary, first affected layer, prevention, detection, containment, recovery, and residual risk before the model is complete.

CHANGED CONDITION

A signature proves authorization and integrity but not freshness or truth, while a layer label alone leaves downstream response and residual exposure unresolved.

Important distinction: A valid digital signature makes external data trustworthy. It proves authorization and integrity under a key. It does not prove freshness, correct source selection, honest measurement, or sound downstream economics.

Text equivalent: The accepted path is enforced by Every threat case names asset, boundary, first affected layer, prevention, detection, containment, recovery, and residual risk before the model is complete. If the required condition changes, A signature proves authorization and integrity but not freshness or truth, while a layer label alone leaves downstream response and residual exposure unresolved.

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Learn the idea

An attack surface is every input, parser, key, dependency, economic assumption, and operator action that can affect a protocol. Consensus divergence means implementations accept different histories. Nonce reuse can expose signing keys. Oracle manipulation corrupts external data, while economic exploits obey code but violate intended incentives. Layered controls prevent, detect, limit, and recover from different failures.

GUIDED EXPLANATION1/5 ideas inspected

Inventory assets and boundaries

List funds, keys, state, availability, privacy, and governance decisions plus every component that can change them.

The worked example follows the explanation

Inspect every idea above to open it.

Important distinction“A valid digital signature makes external data trustworthy.”

It proves authorization and integrity under a key. It does not prove freshness, correct source selection, honest measurement, or sound downstream economics.

FINISH LEARNING FIRST

The questions unlock after every required learning activity

Inspect every guided idea, open the worked example, rebuild its mechanism, and complete the deterministic lesson tool. Your progress is saved automatically.