Conceptual model for asynchronous physical exchanges

[p.b.]

Hello,

I would like to share a conceptual model exploring the problem of asynchronous physical exchanges between parties who do not know each other and are not present at the same time.
The document proposes a possible architecture aiming to reduce some risks inherent to these exchanges while preserving anonymity, avoiding reliance on trusted intermediaries, and separating monetary settlement from physical state coordination.
The goal of the document is not to present a finished implementation but rather a conceptual framework open to discussion and technical critique.

Documents provided:

• French version (original) – complete document (Epasynchroneorigine)

• English version – Part 1 (TradEpasynchronepb1)

• English version – Part 2 (TradEpasynchronepb2)

https://github.com/pbasynch/asynchronous-physical-exchanges.git

The English version was translated from the French text. If any passage seems unclear in English, the French version may be used as the reference.

Feedback, criticism and technical comments are welcome.

[MarryWithBTC]

I have gone through the github file and read through, I have my concerns about the logistics intervention, but I'll have to go through carefully again.
You uploaded the write up as images and not as texts.

[Ucy]

Sounds like the lock would be internet connected or always online machine/electronic. Seems Futuristic, but i doubt has been invented yet.  A machine that's capable of full inspection or review to verify that a product is according to seller's description would be expensive, large, complex, to also be capable of reviewing almost all product type whether small or big, like from watches to cars. I think this is what humans can handle more effectively, but in much slower pace

So, you would ether combine humans and machines, or humans only for the reviews, and still ensure that the whole process or most of it meets your specifications: asynchronous, anonymous, trustless, no intermediary, decentralized, etc
If you want it so, then there has to be physical system for the whole process, and it possibly should be open to anyone to participate or should be permissionless.

 — Firstly, fund is escrowed by buyer after going through a product and the description of its condition. The product and the condition is sent to collection point with a minimum of two reputable witnesses to review and approve/disapprove it based to the condition. Then the buyer comes to the collection point to inspect it too, if it's according to the stated condition, escrowed bitcoin is released.  *Fund should not be released in cases like this until product condition is finally verified and approved by a minimum of 2 witnesses plus the buyer. One witness could be doing the verification while others approving or disapproving. If product fall short of standard, it's returned.

[p.b.]

MarryWithBTC

Thank you for your feedback and for taking the time to go through the document.

Of course, there is no problem if you would like to review it more carefully before sharing further thoughts, especially regarding the logistical part.
Regarding the PDF files, you are right: they were generated from a format that makes the text difficult to copy or select. I plan to make them available soon in a selectable text format to make reading, quoting, and analysis easier.

Thank you


Ucy

Thank you for your response and for your reflections on the model.

You are correct on one point: in this concept, the physical devices (such as lockers or deposit points) would indeed be permanently connected to the network and interact with the layer B infrastructure.
Regarding the machines capable of inspecting objects, I understand your remark. The idea is not to design a universal machine capable of analyzing every possible type of object (for example cars). In this model, devices could instead be specialized depending on the type or category of objects, using sensors and measurement methods adapted to those specific cases.

I also understand your suggestion of introducing human verification. However, one of the main goals of the model is precisely to limit human intervention in the process as much as possible. Introducing witnesses or human inspections reintroduces trusted third parties and reputation-based mechanisms, which this model specifically attempts to avoid in order to preserve properties such as anonymity, the absence of intermediaries, and decentralization.

You also mention that such a system would require a physical infrastructure open and accessible to participants. On this point I agree: the idea would be for the infrastructure to be usable by different actors, while the layer B registry remains open, distributed, and append-only.
Finally, thank you for proposing an alternative model. I understand the logic behind your approach. However, in this case it introduces several trusted third parties (the witnesses responsible for verifying the object), which is precisely one of the elements this model aims to avoid.

In addition, the fact that the buyer must physically inspect the object before the funds are released introduces certain limitations. In such a scenario, situations of collusion could arise, for example between some witnesses and the buyer, or between the buyer and actors present at the collection point. The buyer could potentially leave with the object or validate its conformity in circumstances that no longer truly guarantee a trustless or intermediary-free process.
Furthermore, in this type of mechanism the release of the escrow ultimately depends on a final action from the buyer. If the buyer never shows up to inspect the object, refuses to validate the transaction, or simply disappears, the escrow can remain locked and the exchange cannot be properly finalized. In the model proposed in this document, this type of blockage is specifically avoided through the introduction of time constraints, automatic conditions, and economic commitments between the actors, which helps reduce direct dependence on human decisions within the process.

Thank you again for your response and for your thought

[Ucy]

Sorry for late reply, p.b
I made my suggestion due to tech constrain in the proposal even though it's a very interesting one I wish has the tech capability. My only issue with the proposal apart from the lock is the commitment by the transporter inform of insurance, for goods lost or stolen in transit.. I think that is a gamble you may hardly find anyone that's willing to take unless for products that aren't worth alots.

Concerning the lock, the humans will still be needed until there is tech that is capable of serving that role effectively.

In the case of trust and reputation, mine is actually not trust based since non of the verification or approval of the witnesses  (even the reputable ones)  are unchecked by other witnesses. If there is any issue ignored by any witness, others would identify it and nothing gets approved unless tolerated by the buyer.
 Collusion will be difficult if there is re-verification by other witnesses. And there will be decentralized arbiters to finally release funds from escrow if buyers do not show up for example, after witness reports

[joniboini]

Maybe you should upload the text directly to GitHub. Personally, I'm not comfortable downloading files from the internet if I don't know the uploader at all. We have had many attacks using PDF files on various devices, too, in the last few months or so. It will be easier for people to read and check their understanding of your project, too. Even if you convert it to txt or something else, some people will still feel uncomfortable.

Your project reminds me of a similar project in the past, although it's geared more toward P2P delivery iirc. I can't remember the name though.

[p.b.]

Thank you for your feedback and for the time you have dedicated to reviewing my project. I also apologize for the delay in my response (Ucy).

Joniboini:
Regarding the comment about the document format, I fully understand the concerns related to downloadable files and the potential risks they may carry. I have therefore taken the time to provide a version that is directly accessible online, without any download required, so that the content can be easily and safely reviewed. The text is now readable and selectable (MarryWithBTC).
https://github.com/pbasynch/asynchronous-physical-exchanges/blob/main/README.md

If you happen to remember the similar project you mentioned, I would also be interested in knowing its name. It could be useful to compare approaches. Please feel free as well to review the content and share your thoughts if any points raise questions or interest you.

Ucy:
I will now provide a more detailed response to the questions raised regarding the logistical commitment, its associated responsibilities, as well as the more detailed functioning of the nodes and layer B.

Regarding the transporter’s commitment, particularly in terms of insurance in case of loss or theft, it is important to clarify that this aspect does not fundamentally differ from what already exists today in traditional logistics systems. Transport operators already rely on insurance mechanisms, whether internal or through third-party insurers, depending on the nature and value of the goods being transported. In this context, risk management remains the responsibility of the logistics providers themselves, not the protocol. The system therefore does not introduce a new type of risk, but rather fits within a framework already mastered by transport actors. Concretely, these actors maintain financial reserves or risk-pooling mechanisms that allow them to cover potential losses, as is already the case today. This operates similarly to traditional insurance systems, for example in housing: not all claims occur at the same time, and the system relies on risk mutualization. If an extreme event were to occur simultaneously across all cases, no insurance system could cover all losses, yet this does not prevent such models from functioning effectively in practice. The principle remains the same here.

To avoid any situation in which an item would remain without handling after the buyer’s validation and payment, the system can rely on a set of logistics operators affiliated with the network. These operators, once registered within the infrastructure, accept the protocol rules as well as the cryptographic commitments associated with transport tasks. When an exchange is finalized and the item is locked in the deposit locker, the logistics task can be automatically assigned to one of these operators according to predefined rules. The corresponding cryptographic commitment is then triggered without requiring manual selection. This mechanism ensures that a validated and paid item is not left without a transporter.

Such a mechanism is not fundamentally different from practices already present in e-commerce. When placing an order online, the buyer may choose between several carriers or delivery levels, but once the order is confirmed, the transport task is automatically handled by the selected provider, without the provider individually accepting each package. In this model, logistics operators agree in advance to the protocol rules and associated commitment conditions, making automatic task assignment possible while ensuring process continuity.

Regarding the role of humans, it is indeed likely that current technological limitations still require some level of human intervention in certain cases. However, the objective of this model is precisely to minimize reliance on trust-based human mechanisms, moving toward a system where validation and execution rely primarily on cryptographic commitments and protocol rules rather than reputation or arbitration.
Finally, even with multiple witnesses and re-verification mechanisms, this still introduces forms of trust and potential coordination risks between participants. The goal here is to eliminate these dependencies by design, rather than attempting to mitigate them afterward.

System Compensation:

The system’s compensation relies on protocol fees integrated into the exchange and paid by the buyer, in addition to the logistics cost. These fees are intended to compensate both the logistics operator responsible for the physical transport and the nodes of the distributed infrastructure that ensure the operation of the state layer. Layer B does not constitute a monetary infrastructure and does not create value on its own. The compensation of participants relies exclusively on fees integrated into the underlying economic exchange. These fees, paid by the buyer during the transaction, are then redistributed between the logistics operators and the contributing nodes based on their effective participation.

Unlike systems based on competition or the designation of a single winner, layer B operates on a contribution-based compensation model. Nodes that actively participate in processing a given state—data reception and verification, cryptographic hashing, information propagation across the network, timely validation submission, and participation in the finalization of the state block—are identified by the protocol as contributing nodes.

For each validation sequence, the system records the actions performed by nodes (validation submitted, comparison executed, finalization signature, etc.) and builds a set of active participants. The fees associated with that state are then distributed among these contributing nodes, either equally or proportionally to their effective participation.
This mechanism ensures that nodes are compensated for the actual work performed, without introducing competition, lottery-based rewards, or arbitrary selection. It also enables continuous distribution of incentives, regardless of the rarity or frequency of events, in line with the non-monetary nature of layer B.
At the same time, the logistics operator is compensated through transport fees associated with the physical exchange and assumes, in return, the cryptographic commitment accepted when taking charge of the item.

Anchoring of States in Bitcoin:

To strengthen the resilience and integrity of the state registry, layer B can periodically anchor its data into the Bitcoin blockchain. Validated states are grouped and condensed using a cryptographic structure such as a Merkle tree. The root of this tree, which represents a unique fingerprint of all the associated states, can then be included in a Bitcoin transaction.

This mechanism allows the system to benefit from Bitcoin’s security and immutability while limiting the amount of data actually written to the blockchain. It is acknowledged that the use of the Bitcoin blockchain for anchoring external data should remain minimal so as not to unnecessarily increase the network’s data load, as its architecture is specifically designed to limit such growth. For this reason, anchoring can be performed by grouping states over a given period rather than on a per-transaction basis.

The objective is not to use Bitcoin as a storage layer, but as an external cryptographic reference that publicly attests to the existence and integrity of the states recorded by layer B.
As Bitcoin’s block subsidy decreases over successive halvings and is expected to disappear around 2140, miners will rely primarily on transaction fees to maintain network profitability. In this context, the use of the Bitcoin blockchain as an anchoring layer by external systems could contribute to supporting this fee-based economy.
This practice can increase demand for block space and therefore transaction fees, which may indirectly strengthen miners’ economic incentives. Within this model, the anchored data does not represent the content of physical exchanges themselves, but only a cryptographic proof that a validated event on layer B corresponds to a real operation associated with a transaction on layer A.
As such, this data maintains a direct link with a concrete economic activity. Unlike certain data that can be written to the blockchain without an explicit connection to an economic transaction, the goal here is to reference only real events resulting from an actual exchange.

[p.b.]

Hello,

I've been a bit less available recently, but i've been continuing to work on the model.
In this message, i provide additional details on the définition of a state, as wells as on the node reward mechanism.

Definition of a State :

A state corresponds to an identifiable step in the process.
Each state produces information that must be processed, verified, or stored by Layer B nodes.
A complete cycle can be decomposed as follows:

1/exchange creation
2/initial deposit of the item and capture of its characteristics
3/buyer validation
4/payment on Layer A
5/locker locking
6/logistic pickup
7/final deposit
8/verification and comparison of characteristics
9/retrieval
10/cycle finalization through Merkle root computation and block production on Layer B

Types of States:

Not all states are of the same nature.
Some states are immediately verifiable, as the protocol can validate them directly when they occur.
This includes, for example, exchange creation, buyer validation, payment on Layer A, locker locking, and retrieval.
Other states are provisional when received.
They are recorded as soon as they are transmitted, but their full validity is only confirmed at a later stage.
This is the case for the initial deposit with characteristic capture, logistic pickup, and final deposit.
Their consistency is ultimately established during the verification and comparison phase.

Finalization and Integrity:

Once the complete cycle is finished, nodes aggregate the validated states into a cryptographic structure and compute a Merkle root.
This root represents a synthetic fingerprint of the entire cycle.

It serves two purposes:
-ensuring the internal integrity of the cycle on Layer B
-enabling, if necessary, anchoring into Bitcoin to strengthen the immutability of the recorded history

Node Reward Model:

Node rewards are not based on computational power, nor on direct competition.
The objective is to allow any participant to contribute to the protocol and be rewarded for their participation, without requiring particularly powerful or costly infrastructure.
The model is based on valid participation in defined protocol steps, rather than raw performance.

Operation:

The fees generated by asynchronus physical exchanges are distributed between the logistics layer and the nodes, ensuring their remuneration.
The complete cycle is structured into ten distinct states.
Each state represents a specific step in the process and corresponds to a defined fraction of the total reward.
When a node correctly contributes to the validation of a state, and this contribution remains consistent until the finalization of the entire cycle, it becomes eligible for a reward for that step.
However, rewards are only distributed at the end of the full cycle, once all states have been validated and consolidated.

Thus:
-a node that contributed to a single validated state receives 10% of the reward associated with the exchange
-a node that participated in multiple states receives a proportionally higher reward

Distribution Principle:

The total reward associated with an exchange is divided into ten equal parts, each corresponding to one state of the cycle.
Each part is allocated to the nodes that effectively contributed to the validation of that state, provided that their contribution remains consistent with the final state accepted by the protocol.
This mechanism ensures that only valid participation across the full cycle is rewarded, and prevents isolated or inconsistent contributions from being rewarded.

This model does not prevent an actor from deploying a large number of nodes.
However, in practice, increasing the number of nodes involves hardware, energy, and operational costs that are not necessarily offset by the rewards obtained.
Since the protocol is accessible without costly infrastructure, a large number of independent participants can contribute concurrently, which tends to balance reward distribution.

[p.b.]

This is a conceptual pre-modeling of, the protocol, prior to implementation and may require further refinement.

State 1 — Exchange Creation:

State 1 corresponds to the creation of an exchange on Layer B.
It initializes the cycle by registering the cryptographic identities of the participants, a unique exchange identifier, and the minimal protocol parameters..

exchange_id
state_type = CREATE
prev_state = null
timestamp
seller_pubkey
buyer_pubkey
origin_locker_id
destination_locker_id (optional)
logistic_policy
logistic_service_level
logistic_auto_assignment = true
logistic_guarantee_policy
logistic_activation_condition
protocol_conditions
nonce
seller_signature
buyer_signature
node_validation_set
node_completion_status
eligible_node_count
state_reward_share = 10%

State 2 — Initial Deposit:

State 2 corresponds to the moment when the seller physically deposits the item into the origin locker.
At this stage, the locker system captures the item’s technical characteristics, computes an initial technical fingerprint, and Layer B emits a protocol-level temporary lock instruction.
The locker enforces this rule locally according to protocol conditions, for example a 24-hour lock.

exchange_id
state_type = INITIAL_DEPOSIT
prev_state = state_1_id
timestamp
temporary_lock_duration = 24h
buyer_validation_window = 24h
seller_reclaim_policy = SELLER_AUTH_AFTER_VALIDATION_EXPIRY
seller_pubkey
locker_id_origin
sensor_data_hash
technical_fingerprint_hash
capture_proof
locker_lock_status = LOCKED
seller_signature
node_validation_set
node_completion_status
eligible_node_count
state_reward_share = 10%

State 3 — Buyer Validation:

State 3 corresponds to the buyer validating the item’s characteristics.
Based on the data captured during the initial deposit, the buyer cryptographically confirms acceptance of the item as recorded in the protocol.
This state does not yet trigger payment or logistics; it simply authorizes progression to the monetary phase.

exchange_id
state_type = BUYER_VALIDATION
prev_state = state_2_id
timestamp
buyer_pubkey
validated_fingerprint_hash
buyer_decision = ACCEPTED
buyer_signature
node_validation_set
node_completion_status
eligible_node_count
state_reward_share = 10%

State 4 — Payment Confirmation:

State 4 records the payment made by the buyer on Layer A.
The buyer submits the transaction identifier (txid) to Layer B, which monitors its confirmation on the underlying blockchain.
The state is only considered valid after sufficient confirmations.
No operational action is triggered at this stage; this state only establishes cryptographic proof of payment and enables transition to execution.

exchange_id
state_type = PAYMENT_CONFIRMATION
prev_state = state_3_id
timestamp
buyer_pubkey
payment_layer = LAYER_A
payment_tx_id
payment_amount
payment_asset = BTC
payment_recipient_address
payment_status
required_confirmations = 1
buyer_signature
node_validation_set
node_completion_status
eligible_node_count
state_reward_share = 10%

State 5 — Execution Lock & Logistic Activation:

State 5 locks the locker for logistic execution and activates the logistic commitment.
At this point, a predefined portion of the logistic guarantee is allocated and cryptographically bound to the exchange, referencing both the exchange_id and the payment transaction.
This activation also triggers a time window (one working day) during which the logistic operator must pick up the item.

exchange_id
state_type = EXECUTION_LOCK
prev_state = state_4_id
timestamp
execution_lock_status = LOCKED
logistic_assignment_status = ASSIGNED
assigned_logistician_id
logistic_commitment_status = ACTIVE
logistic_guarantee_pool_reference
logistic_guarantee_allocation_rule
logistic_guarantee_allocated_amount
logistic_guarantee_exchange_binding
logistic_pickup_deadline = 1_WORKING_DAY
locker_id_origin
activation_trigger = PAYMENT_CONFIRMED
node_validation_set
node_completion_status
eligible_node_count
state_reward_share = 10%

State 6 — Logistic Pickup:

State 6 corresponds to logistic pickup.
The locker opening and item retrieval are recorded as technical proofs and validated by the protocol. From this point onward, the item is under logistic responsibility.
This state also triggers the delivery timeframe. A delivery deadline is computed based on the expected delivery time plus a safety margin.
If the item is not deposited in the destination locker before this deadline, the protocol may handle the failure according to predefined rules.

exchange_id
state_type = LOGISTIC_PICKUP
prev_state = state_5_id
timestamp
assigned_logistician_id
logistic_action = PICKUP_CONFIRMED
locker_id_origin
locker_open_event
pickup_proof
pickup_timestamp
delivery_expected_time
delivery_safety_margin = 5_DAYS
delivery_deadline
logistic_commitment_timeout
logistic_signature
node_validation_set
node_completion_status
eligible_node_count
state_reward_share = 10%

State 7 — Final Deposit:

State 7 corresponds to the final deposit.
The logistic operator deposits the item into the destination locker. This operation is recorded through technical proofs and validated as a deposit event.
The item’s technical characteristics are captured at this stage to produce a final fingerprint. No conformity validation is performed yet.
A pickup window is opened for the buyer. The comparison between initial and final fingerprints is performed in the next state.

exchange_id
state_type = FINAL_DEPOSIT
prev_state = state_6_id
timestamp
assigned_logistician_id
logistic_action = DEPOSIT_CONFIRMED
locker_id_destination
locker_deposit_event
delivery_proof
delivery_timestamp
technical_fingerprint_hash_final
locker_lock_status = LOCKED
buyer_pickup_deadline = 5_DAYS
logistic_signature
node_validation_set
node_completion_status
eligible_node_count
state_reward_share = 10%

State 8 — Characteristic Verification:

State 8 corresponds to verification and comparison of characteristics.
Layer B compares the initial fingerprint with the final fingerprint recorded at the destination locker.
If they match, the item is considered compliant according to the protocol. The locker remains locked, and a five-day pickup window is maintained for the buyer.

exchange_id
state_type = CHARACTERISTIC_VERIFICATION
prev_state = state_7_id
timestamp
locker_id_destination
technical_fingerprint_hash_initial
technical_fingerprint_hash_final
comparison_method_reference
comparison_result = MATCH
comparison_proof
verification_status = VERIFIED
buyer_pickup_window = 5_DAYS
locker_lock_status = LOCKED
node_validation_set
node_completion_status
eligible_node_count
state_reward_share = 10%

State 9 — Buyer Retrieval:

State 9 corresponds to item retrieval.
The buyer opens the destination locker under protocol-defined conditions and retrieves the item.
This action is recorded through technical proofs and confirmed cryptographically. The physical exchange is now completed.

exchange_id
state_type = BUYER_RETRIEVAL
prev_state = state_8_id
timestamp
buyer_pubkey
locker_id_destination
buyer_authentication_proof
locker_open_event
retrieval_proof
retrieval_timestamp
buyer_confirmation_signature
node_validation_set
node_completion_status
eligible_node_count
state_reward_share = 10%

State 10 — Finalization:

State 10 closes the cycle.
It no longer corresponds to a physical action, but to a synthesis and integrity operation performed by Layer B.
Nodes aggregate all validated states, compute the Merkle root, and produce the corresponding block on Layer B.

exchange_id
state_type = FINALIZATION
prev_state = state_9_id
timestamp
cycle_state_count = 10
cycle_completion_status = COMPLETED
merkle_root
block_inclusion_status = CONFIRMED
optional_anchor_reference
node_reward_distribution_status = READY
node_validation_set
node_completion_status
eligible_node_count
state_reward_share = 10%

[Vod]

OP - try to build solid understanding of your ideas before you go into details.  When I see walls of text like yours, I think about all the free image generators that are available.  Many workflow diagrams exist that can help the "less" technical understand your idea. 

[p.b.]

Vod

Thanks for your comment

I initially chose a text-based format because i thought it would be readable and understandable for everyone, as i believe that anyone, regardless of their technical level, can understand and can contribute to improving the model, that is the goal.

That said, i understand your point about visualization, and i will work on representing the process in a more visual way to make it easier to follow.

It may take me a bit of time, but i  will provide a clearer visual representation.

[p.b.]

Hello,

I’ve added a visual representation at the beginning of the Readme : https://github.com/pbasynch/asynchronous-physical-exchanges/blob/main/README.md

This visual representation is meant to provide a clearer and more intuitive understanding of the full process. Combined with the written explanations and previous messages, it should make the overall model much easier to follow.

I also made a small update in State 8:
I added two pre-modeling lines related to the release of the logistic commitment, which were missing in my previous explanation.

This version is intentionally simplified to make it accessible and easy to understand.
The goal is for anyone, regardless of their technical level, to be able to grasp the system, think about it, and suggest improvements.

[joniboini]

I find it hard to read your visual diagram. For example, the text is too small, and enlarging the image is a bit annoying on GitHub because we need to open a new tab for that. In addition to that, the text color for the "Locker" part is also hard to read because it's read on a blue background (even the light blue one is hard to read too imo). It's a bit difficult to understand what each label/arrows/state mean unless reading the full course is necessary for that. Maybe you can improve the image further? Or host it on another place that makes it easier to zoom in on the image.

[MarryWithBTC]

MarryWithBTC

Thank you for your feedback and for taking the time to go through the document.

Of course, there is no problem if you would like to review it more carefully before sharing further thoughts, especially regarding the logistical part.
Regarding the PDF files, you are right: they were generated from a format that makes the text difficult to copy or select. I plan to make them available soon in a selectable text format to make reading, quoting, and analysis easier.

Thank you

I bookmarked this thread and I am glad to  be here again.

It seems that you have done a lot of work by changing the format of the white paper and you also followed Vod's advice by producing a visual representation.

i now understand deeper about the project. I have not finished the whitepaper but i must confess that this is a complex project that will involve global coordination of infrastructure.

This will also require specialized hardwares - lockers with high or advanced sensors.

I have a lil concern about the "no third party trust."

from layer a, it is very trustless but in layer b, trust is not totally eliminated. Rather users have to trust hardwares not to fail, give inaccurate measurements.

How about the logistics and delayed delivery; any proven way to handle it?

P.S is this an individual project or you are open for collaboration.

I find it hard to read your visual diagram. For example, the text is too small, and enlarging the image is a bit annoying on GitHub because we need to open a new tab for that. In addition to that, the text color for the "Locker" part is also hard to read because it's read on a blue background (even the light blue one is hard to read too imo). It's a bit difficult to understand what each label/arrows/state mean unless reading the full course is necessary for that. Maybe you can improve the image further? Or host it on another place that makes it easier to zoom in on the image.

The visual is okay from my end.
May I ask the device you read from. Yes, the color combination of the "locker" is eyes straining

[Vod]

This visual representation is meant to provide a clearer and more intuitive understanding of the full process.

It does not do that.     There is nothing intuitive about walls of text inside shapes.   You should build a very basic flowchart and use just a few words to describe each step.    Once people understand the concept they can file the mass of data more easily. 

[p.b.]

Hello,

Joniboini/Vod

I understand that the first version was not easy to read or interpret. I have therefore reworked the visuals into a much more simplified version, with a clearer structure and improved readability.
I have deliberately reduced the complexity as much as possible.https://github.com/pbasynch/asynchronous-physical-exchanges/blob/main/whitepaper/README.md
Thank you for your feedback.

MarryWithBtc:

Thank you for your message and for taking the time to go through the project.
You are absolutely right regarding the complexity — the model would indeed require a significant level of infrastructure coordination, as well as specialized hardware if it were to be implemented in practice.

Regarding the “no third party trust” aspect, I agree with your observation. The model does not completely eliminate trust in the physical layer. Instead, it aims to reduce it and constrain it through measurable and verifiable physical data. The idea is not to remove trust entirely, but to replace arbitrary trust with physical and economic constraints.

Regarding logistics and delayed delivery, this is handled through an economic commitment mechanism combined with a time constraint. The logistics is engaged via a conditional transaction. If the delivery is not completed within the defined time — whether due to delay, loss, or damage — the simple passage of time makes the transaction executable in favor of the buyer. This removes the need for arbitration and ensures a deterministic outcome.

Regarding your last question, this is a work that I have developed individually.
It is nevertheless designed as an open framework for discussion and improvement.
Anyone interested is free to think about the model, develop it, contribute to it, and exchange ideas in this discussion with the goal of improving and evolving it.

[d5000]

I like the design a bit. I have thought about a somewhat related design for a kind of "ATM" to facilitate P2P exchanges with cash, to avoid both parties being present physically in the same place at the same hour, both for convenience (so people can for example fill several orders at once in a city at once) and privacy (because they don't have to see the others' face).

Your design has made me think a bit about that concept again and has led to a revision of that concept. It would not require specialized hardware, but have a slight drawback: an escrower must coordinate a videochat (without face contact being necessary) with the buyer (i.e. the person who opens the locker and retires the cash or another good). It would also be suitable for the exchange for physical goods vs. Bitcoin.

[p.b.]

Hello,

d5000

Thank you for your feedback and for taking the time to read my model.

I understand your idea of a system involving lockers and an escrower coordinating a video call. It is an interesting approach, especially from a practical point of view, as it reduces the need for specialized infrastructure while still maintaining a certain level of trust and coordination.

In my case, i intentionally explored a more complex conceptual model. The goal was to push decentralization as far as possible and to reduce reliance on trusted third parties, even though i agree that this is extremely difficult to achieve in the physical world.

Beyond the exchange mechanism itself, i also believe there is an important missing layer in the current ecosystem: non-monetary blockchains, such as state and coordination layers. In my opinion, they are just as important as monetary blockchains.

Today, we already see people anchoring various types of data directly into Bitcoin. While Bitcoin is extremely robust, decentralized, and libertarian in nature, it is not entirely clear whether it was designed to support all kinds of data. In my model, anchoring data in Bitcoin is limited to cases where it is directly related to a Bitcoin transaction. In that sense, it can be seen as a kind of cryptographic receipt attached to the payment.

However, for broader use cases, i believe that a state and coordination blockchain, like the one i propose, could be used to anchor data, proofs, or states in a decentralized way, without overloading a monetary blockchain like Bitcoin.

Of course, building such a blockchain in a secure and truly decentralized way is a major challenge today, especially in terms of resistance to attacks and ensuring data integrity. But I believe this is an important direction to explore.

[d5000]

Beyond the exchange mechanism itself, i also believe there is an important missing layer in the current ecosystem: non-monetary blockchains, such as state and coordination layers. In my opinion, they are just as important as monetary blockchains.

Are you really sure you need a blockchain?

Blockchains solve one issue very well: the double spend problem in a trustless environment. But what can be double spent in such a situation? And who can double spend it and would damage exactly whom? I don't rule out there is a step in your design where a blockchain would be necessary, but it may be fruitful to think about that question.

In Bisq for example not all steps correspond to a blockchain state. In most state changes, only buyer, seller (and later escrower) communicate, and they also define (in agreement) the step sequence they're in. They can't "trick" each other into e.g. accepting another sequence of steps because everybody has to sign cryptographically their messages and timestamps, and thus it's always clear who did what in which phase if the communication protocol is properly designed (e.g. that every participant has to sign the whole ledger of communication steps, like in systems like Scuttlebutt). In your design there's a third party, a logistics operator.  Communication between these three parties isn't really complex. The logistics operator could, in your case, be the entity giving the instruction to the locker to open or get locked, if the communication between buyer and seller reaches the point where they agree about the purchase. The locker software not necessarily needs to consult "a blockchain" for that.

In the case you need one step where you really need a blockchain, you can also use an existing one, with a mechanism like OP_RETURN to store the data for bitcoin-based blockchains (some interesting choices could be LTC or Dogecoin, maybe also Kaspa would be interesting because it doesn't need to record all states all the way to genesis block forever, only the recent ones). The problem is that a pure non-monetary blockchain lacks a proper incentive mechanism. So I would look into these hybrid chains - both LTC and Doge communities openly embrace data transactions afaik.

[MarryWithBTC]

Regarding the “no third party trust” aspect, I agree with your observation. The model does not completely eliminate trust in the physical layer. Instead, it aims to reduce it and constrain it through measurable and verifiable physical data. The idea is not to remove trust entirely, but to replace arbitrary trust with physical and economic constraints.

Thank you for the clarification, I think we are now aligned on the idea that the system is more about constraining trust and not eliminating it in its entirety as i erroneously thought.

Regarding your last question, this is a work that I have developed individually.
It is nevertheless designed as an open framework for discussion and improvement.
Anyone interested is free to think about the model, develop it, contribute to it, and exchange ideas in this discussion with the goal of improving and evolving it.

That is great, I wish you success on this project. It is actually a project intending to solve a pressing problem.