Protocol for Requesting and Sharing Views across Networks
draft-ramakrishna-satp-data-sharing-01
| Document | Type | Active Internet-Draft (individual) | |
|---|---|---|---|
| Authors | Venkatraman Ramakrishna , Vinayaka Pandit , Ermyas Abebe , Sandeep Nishad , Dhinakaran Vinayagamurthy | ||
| Last updated | 2024-01-08 | ||
| Replaces | draft-ramakrishna-sat-data-sharing | ||
| RFC stream | (None) | ||
| Intended RFC status | (None) | ||
| Formats | |||
| Additional resources |
GitHub Repository
GitHub Organization GitHub Username: VRamakrishna |
||
| Stream | Stream state | (No stream defined) | |
| Consensus boilerplate | Unknown | ||
| RFC Editor Note | (None) | ||
| IESG | IESG state | I-D Exists | |
| Telechat date | (None) | ||
| Responsible AD | (None) | ||
| Send notices to | (None) |
draft-ramakrishna-satp-data-sharing-01
Internet Engineering Task Force Venkatraman Ramakrishna
Internet-Draft IBM Research
Intended status: Informational Vinayaka Pandit
Expires: July 8, 2024 IBM Research
Ermyas Abebe
Consensys
Sandeep Nishad
IBM Research
Dhinakaran Vinayagamurthy
IBM Research
January 8, 2024
Protocol for Requesting and Sharing Views across Networks
draft-ramakrishna-satp-data-sharing-01
Abstract
With increasing use of DLT (distributed ledger technology) systems,
including blockchain systems and networks, for virtual assets, there is a
need for asset-related data and metadata to traverse system boundaries
and link their respective business workflows. Systems and networks can
define and project views, or asset states, outside of their boundaries,
as well as guard them using access control policies, and external agents
or other systems can address those views in a globally unique manner.
Universal interoperability requires such systems and networks to request
and supply views via gateway nodes using a request-response protocol. The
endpoints of this protocol lie within the respective systems or in
networks of peer nodes, but the cross-system protocol occurs through the
systems’ respective gateways. The inter-gateway protocol that allows an
external party to request a view by an address and a DLT system to return
a view in response must be DLT-neutral and mask the internal
particularities and complexities of the DLT systems. The view generation
and verification modules at the endpoints must obey the native consensus
logic of their respective networks.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on November 8, 2023.
Copyright Notice
Copyright (c) 2022 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents (https://trustee.ietf.org/
license-info) in effect on the date of publication of this document.
Please review these documents carefully, as they describe your rights
and restrictions with respect to this document. Code Components
extracted from this document must include Revised BSD License text as
described in Section 4.e of the Trust Legal Provisions and are
provided without warranty as described in the Revised BSD License.
1. Introduction
Blockchain systems, especially those of the permissioned variety, are a
heterogeneous mix, fulfilling a diverse range of needs and built on
several different DLT stacks that are not compatible with each other.
Yet, in an interconnected world, the business processes running on each
system cannot afford to remain isolated and the virtual assets they
manage cannot afford to remain in siloes. These systems must be
interoperable so that assets can move, and their properties can be
reflected across network boundaries, and so that business processes can
span multiple systems. Interoperability will, in effect, mimic a larger
or scaled up, blockchain system composed of smaller blockchain systems
without explicitly requiring those systems to coalesce.
At the core of any cross-blockchain system transaction is the ability of
a system to project a view of assets and associated data recorded on its
ledger to external parties, be they individual agents or other blockchain
systems. On the reverse, a blockchain system must also have the ability
to identify and address views of assets or associated data in another
system, and further, to validate that view before its business process
consumes it. View projection, addressing, and consumption, must
eliminate or minimize the role of third parties to avoid loss of data
privacy, control over business process, or diminishment of autonomy.
This document specifies an end-to-end protocol whereby a view request and
the corresponding view response can be communicated using two or more
gateway nodes connected to the end DLT systems. The gateways communicate
with each other using a DLT-neutral protocol (like SATP [SATP], or
variations of it) and therefore the view requests and responses must be
encapsulated in DLT-neutral data formats. Beyond the gateways, and into
the DLT systems, view generation and consumption rely upon native
mechanisms exposed by those systems. The gateways must therefore be
augmented to exercise these mechanisms to convey view requests and
responses to their respective back-end systems.
The purpose of this document is to provide a technical framework
to discuss the various aspects of a basic view request-response
protocol via gateways acting on behalf of blockchain/DLT systems,
including security and privacy considerations.
2. Terminology
There following are some terminologies used in the current document:
o Blockchain system: Blockchains are distributed digital ledgers of
cryptographically signed transactions that are grouped into
blocks. Each block is cryptographically linked to the previous
one (making it tamper evident) after validation and undergoing a
consensus decision. As new blocks are added, older blocks become
more difficult to modify (creating tamper resistance). New blocks
are replicated across copies of the ledger within the network, and
any conflicts are resolved automatically using established rules
[NIST].
o Blockchain network: This is a blockchain system that is built on a
network of nodes that maintain a common shared copy of the blockchain
using a consensus protocol.
o Distributed ledger technology (DLT) system: Technology that
enables the operation and use of distributed ledgers, where the
ledger is shared (replicated) across a set of DLT nodes and
synchronized between the DLT nodes using a consensus mechanism
[ISO]. Every blockchain system is also a DLT system, and so we
will mostly use the latter term in this draft when discussing
protocols for cross-system interactions.
o Distributed ledger network: This is a DLT system that is built on a
network of nodes that maintain a shared copy of the ledger or portions
of it on different subsets of nodes using a consensus protocol.
o Resource Domain: The collection of resources and entities
participating within a blockchain or DLT system. The domain
denotes a boundary for permissible or authorized actions on
resources.
o Interior Resources: The various interior protocols, data
structures and cryptographic constructs that are a core part of a
blockchain or DLT system. Examples of interior resources include
the ledger (blocks of confirmed transaction data), public keys on
the ledger, consensus protocol, incentive mechanisms, transaction
propagation networks, etc.
o Exterior Resources: The various resources that are outside a
blockchain or DLT system, and are not part of the operations of
the system. Examples include data located at third parties such
as asset registries, ledgers of other blockchain/DLT systems, PKI
infrastructures, etc.
o Nodes: The nodes of the blockchain or DLT system which form the
peer-to-peer network, which collectively maintain the shared
ledger in the system by following a consensus algorithm.
o Gateway nodes: The nodes of the blockchain or DLT system that are
functionally capable of acting as a gateway in an asset transfer.
A gateway node conforms to the Secure Asset Transfer Architecture
[SATA] and implements the Secure Asset Transfer Protocol (SATP)
[SATP]. Being a node on the blockchain/DLT system, a gateway has at
least read access to the interior resources (e.g., ledger) of the
blockchain. Optionally, it may have write access to the ledger and
also the ability to participate in the consensus mechanism deployed
for the system. Depending on the blockchain/DLT system
implementation, some or all of the nodes may be gateway-capable.
o Gateway device identity: The identity of the device implementing
the gateway functions. The term is used in the sense of IDevID
(IEEE 802.1AR) or EK/AIK (in TPM1.2 and TPM2.0) [IDevID].
o Gateway owner: The VASP who legally owns and operates a gateway
node within a blockchain system.
o Clients: Entities are permitted to invoke smart contracts to read
or update ledger state in a blockchain or DLT system. They possess
unique identities in the form of public keys. In a permissioned
system, identity certificates are issued by the system's internal
providers (or certificate authorities).
o Wallets: Collection of client identities represented by public-
private key pairs, and optionally certificate issued by a
blockchain or DLT system's identity providers (or certificate
authorities).
o Virtual Asset: A virtual asset is a digital representation of
value that can be digitally traded, or transferred as defined by
the FATF [FATF].
o Virtual Asset Service Provider (VASP): Legal entity handling
virtual assets as defined by the FATF [FATF].
o Ledger state: A snapshot of the information held in a distributed
shared ledger, typically (though not necessarily) as a set of
blockchain or DLT system. Examples of interior resources include
key-and-value pairs. This information includes records of virtual
assets and the state of business processes that are meaningful to
the DLT system's participants and clients. State elements and
subsets may be scoped under the namespaces of given smart contracts,
thereby being accessible only through invocations on those contracts.
o Smart contracts: Business workflows written in programming languages
that manage the states of assets and business processes on a shared
ledger in a DLT system. These contracts constrain the ability of
system clients to modify ledger state and embed guards around state
elements. Contracts can be invoked to read from, or write, to, a
ledger. They can be deployed on several system nodes, who must
agree on a given ledger state update via a consensus protocol.
o Consensus protocol/mechanism: Process by which nodes agree on a
ledger state update, typically (though not mandatorily) through a
smart contract invocation.
o Local transaction: A transaction triggered by a client to update
the ledger state in a blockchain or DLT system, typically (though not
mandatorily) through a smart contract invocation.
o View: A projection of a blockchain or DLT system's ledger state
for external consumption, i.e., for parties outside that system.
This can be a single element, a subset of the state, or a function
over a subset.
o View Address: A unique identifier or locator for a view into a
blockchain or DLT system's ledger. This is analogous to an HTTP URL.
o Source system: Blockchain or DLT system governing the ledger from
which a view is produced.
o Destination system: System in which a view is consumed. This can
be a blockchain or DLT system.
o Remote system: Counterparty system in a view request-response
protocol instance. From the vantage point of the source system,
this refers to the destination system, and vice versa.
o View requestor: Person or organization triggering a view request
from a source network.
o Proof: A data structure containing evidence linking a view to its
source system's blockchain, or more generally, ledger. The evidence
may be probabilistic and in some cases cryptographically verifiable.
o Access/exposure policy: Set of rules governing the release of a view
to an external party (i.e., outside the source system), held in
consensus by nodes on the source system's ledger.
o Verification policy: Rules for validation of proofs associated with
views maintained in a destination system. If the destination system
is a blockchain or DLT system, these rules are held in consensus by
nodes on the that system's ledger.
o View Request: A request for a made by an external party to a source
blockchain or DLT system. The external party may be a client in
a destination blockchain or DLT system. The request consists of a
view address and various metadata, including optionally a
verification policy.
o Asset locking or escrow: The conditional mechanism used within a
blockchain or DLT system to make an asset temporarily unavailable
for use by its owner. The condition of the asset release can be
based on a duration of time (e.g., hash time locks) or other
parameters.
o Gateway crash recovery: The local process by which a crashed
gateway (i.e., device or system fault) is returned to a consistent and
operational state, ready to resume the asset transfer protocol with
the peer gateway prior to the crash event.
Further terminology definitions can be found in [NIST] and [ISO].
The term 'blockchain' and 'distributed ledger technology' (DLT) are
used interchangeably in this document.
3. Assumptions and Principles
The following assumptions and principles underlie the design of the
current interoperability architecture and protocol enabling the
requesting and sharing of data from across DLT systems using gateways,
and correspond to the design principles of the Internet architecture.
3.1. Design Principles
The protocol must not involve any centralized intermediaries or trusted
third parties, including settlement blockchains, other than gateways. The
protocol must not decrease the security of endpoint blockchain systems
nor impose a higher bar on their internal consensus. Further, the
protocol must not reveal any private information from a system beyond
what the nodes of that network have agreed to through consensus. The
protocol must enable view requests and response from systems built on any
arbitrary (present or future) blockchain or distributed ledger
technology. Finally, the endpoint systems must retain full autonomy over
internal governance and framing of policies governing how views can be
exposed and how proofs can be validated.
3.2. Operational Assumptions
The following conditions are assumed to have occurred prior to the
construction of a view request:
o Syncing remote system structure, memberships, and identities: see
Section 10 for details.
o Recording view access control policies in the source ledger: see
Section 10 for details.
o Recording view verification policies in the destination ledger: see
Section 10 for details.
4. Interoperability and Data Sharing Among Distributed Ledger Systems
Distributed ledger systems, typically maintained through consensus on a
network of peer nodes, run business workflows (often as “smart contracts”
[Ethe22]) and maintain transaction logs. The ledgers and their
transaction histories are distinct, but the business workflows they run
are often interlinked in the real world. This necessitates
interoperability among the systems/networks as well as the ledgers
maintained by them. Certain modes, or patterns, of interoperability have
been identified as typical and useful for the enterprises and consortia
that run these systems. These are listed in the Secure Asset Transfer
architecture draft [SATA], namely as asset transfer, asset exchange, and
data sharing, respective. Motivating use cases for these different modes
have been presented in the Secure Asset Transfer use cases draft [SATU].
In this document, we will address the data sharing mode of
interoperability, whereby DLT systems can export views of their ledger
state with associated proofs of authenticity, control access to these
views, and also address views exported by a remote DLT system. The
formats of the views, addresses, requests, and access control policies
are beyond the scope of this draft, and are specified in the Views and
View Addresses draft [SATV]. This draft specified a request-response
protocol whereby a view can be requested from one DLT system to another
via those systems’ respective gateways, and obtained and consumed via the
same gateways. In effect, data maintained on the ledger in one system is
shared with another in a way that requires no third-party system or agent
acting as a mediator.
This draft will only specify a bilateral protocol, i.e., whereby a view
is requested by a DLT system to exactly one other DLT system and whereby
a view is supplied by a DLT system with exactly one other DLT system.
Extrapolating or augmenting this protocol to involve more than two DLT
systems is beyond the scope of the present draft.
5. Data Sharing Protocol
This section describes a protocol using which an external entity can
request and process a view from a distributed ledger.
5.1. Goal and Overview of Protocol
Using this protocol, any entity, be it a single application or agent or a
distributed ledger system itself, can supply a view address and a
verification policy to a distributed ledger system and obtain a view in
response, which it can then validate before processing as per need. This
protocol makes no assumption about the nature of such processing, which
can be executed by some module (like a smart contract) but rather
prescribes the steps to be followed until the point where the view is
dispatched to the module.
The diagram below illustrates the protocol whereby a distributed ledger
system requests and consumes a view from another distributed ledger
system. The protocol units are indicated, with sequence numbers
associated with procedures or messages.
+----------------------------+
| Client |
| (Application) |
+----------------------------+
| ^ |
| 7 View | |
8 View | Response | | 1 View
| | | Request
V | V
+----------------+ +---------+ +---------+ +----------------+
| | | | 2 View | | | |
| DLT L1 | | | Request | | | DLT L2 |
| | | |-------->| | 3 | |
| +------------+ | | Gateway | | Gateway |-->| +------------+ |
| | 9 View | |---| G1 | | G2 | | | 4 Access | |
| | Validation | | | | | |<--| | Control & | |
| | & | | | |<--------| | 5 | | View | |
| | Commitment | | | | 6 View | | | | Generation | |
| +------------+ | | | Response| | | +------------+ |
+----------------+ +---------+ +---------+ +----------------+
In a shorter form of the protocol, the requesting system is a unitary
entity rather than a network of peers maintaining a distributed ledger
and a client application above it. The diagram below illustrates this
protocol and its units, with sequence numbers associated with procedures
or messages.
+-----------------------+ +---------+ +----------------+
| | 1 View | | | |
| Client | Request | | | DLT L |
| (Application) |----------->| | 2 | |
| | | Gateway |-->| +------------+ |
| +-------------------+ | | G | | | 3 Access | |
| | 6 View Validation | | | |<--| | Control & | |
| | & Commitment | |<-----------| | 4 | | View | |
| +-------------------+ | 5 View | | | | Generation | |
| | Response | | | +------------+ |
+-----------------------+ +---------+ +----------------+
The distributed ledger system on the right is referred to as the source
system, as it is the source of the information being requested for
through a view. The system on the left is referred to as the destination
system, as the desired information ends up there either in raw or in
processed form. The destination system can be a traditional centrally
governed system or a distributed ledger system maintained by a
decentralized network.
5.2. Protocol Phases
The protocol can be divided into the following phases:
o Phase 1: View request creation in destination network.
o Phase 2: Cross-gateway discovery and request.
o Phase 3: View creation in source network.
o Phase 4: Cross-gateway response.
o Phase 5: View validation and commitment in destination system.
5.3. Phase 1: View request creation in destination network
All operations in this phase are conducted by a client, typically acting
through an application, in the destination system.
o The client constructs a view address corresponding to the desired
view.
o The client looks up the verification policy corresponding to this view
address from the destination system’s database. If the destination
system is a distributed ledger system, this lookup should involve a
query to one or more shared ledgers within the system.
o The client sends a view request comprising of the view address and the
verification policy to the destination system’s gateway.
5.4. Phase 2: Cross-gateway discovery and request
All operations in this phase are conducted by a gateway belonging to, or
acting on behalf of, the destination system.
o The destination system’s gateway looks up or tried to discover the
address of one or more gateways belong to, or working on behalf of,
the source system. If no address can be found, the protocol
terminates.
o The destination system’s gateway selects an address and sends the view
request to the source system’s gateway at that address.
5.5. Phase 3: View creation in source network
Operations in this phase are orchestrated by a source system gateway via
the system’s smart contract transaction and network consensus mechanisms.
o The source system’s gateway converts the view request into a
distributed ledger query or a smart contract invocation (if the source
system supports smart contracts). The following steps show how this
happens in a permissioned distributed ledger system with smart
contracts.
o The source system’s gateway parses the view address within the view
request to formulate a view data query and determine the ledger
from which a view is desired.
o The source system’s gateway parses the verification policy in the
view request to determine a subset of peers within its network that
maintain this ledger and to which this query can be sent.
o The source system’s gateway invokes a smart contract to process the
view data query, in effect by sending the query to the selected
network peers.
o Each peer that receives the query:
o Validates the query against the source system’s access control
policy.
o Processes the query and produces an output if the validation is
successful.
o Packages and signs the output, which can be a query response or
a failure report, as it would do with any regular smart contract
transaction result. The signature constitutes part of the proof
for satisfaction of the verification policy.
o Sends the signed package to the source system’s gateway.
o The source system’s gateway creates a view from the smart contract
invocation result. If this invocation follows the process described in
the preceding steps, this is done by collecting and enveloping the
received packages into a view structure.
5.6. Phase 4: Cross-system response
o The source system’s gateway sends the view to the destination system’s
gateway. It may do this as a response in a long-running session that
began with the latter sending a view request to the former.
Alternatively, this could be done by the former posting an event to
the latter. Sending of the view could be a best effort process or
guaranteed through suitable fault tolerance mechanisms built into
gateways. Such mechanisms are beyond the scope of this draft.
o The destination system’s gateway sends the view to the client that
created the original view request. The same mechanisms and
considerations apply as in the cross-gateway response in the preceding
step.
5.7. Phase 5: View validation and commitment in destination system
All operations in this phase are conducted by the client in the
destination system that created the original view request.
o The client parses the view to determine if the request was successful.
If not, the protocol terminates.
o If the destination system is a centrally governed system with a
database, the client submits a transaction, using an available API,
with the view in the arguments. If the destination system is a
distributed ledger system, the client submits a smart contract
transaction, with the view in the arguments, to the destination
system’s network peers.
o The backend system (if the destination system is centrally governed)
or every peer in the network (if the destination system is a
distributed ledger system) that receives the transaction validates the
proof within the view against the verification policy recorded in the
database or the shared ledger.
o If the proof is determined to be invalid, the protocol terminates.
Otherwise, the transaction is executed and then committed to storage,
either through a unitary procedure (centrally governed system) or
through distributed consensus (distributed ledger system).
5.8. Desirable Properties of Data Sharing Protocols
The desirable properties of a data sharing protocol include, but are not
limited to, the following:
o Decoupling gateways from systems: the protocol should not rely on a
specific implementation of a gateway or a cross-gateway communication
protocol, nor should the protocol be restricted to a particular pair
of view generation-validation processes in the respective systems.
Different components and even systems can be replaced without
requiring modifications to the high-level protocol semantics.
o Technology-neutral cross-gateway communication: the cross-gateway
communication protocol, e.g., SATP [SATP], should be oblivious to the
nature and implementation of the endpoint systems. As a corollary, the
protocol units internal to the system should also be oblivious to the
cross-gateway discovery and communication mechanisms.
o Trust through native consensus: end-to-end trust should be realized by
implementing the view generation and validation procedures the same
way as any distributed consensus-driven operation in the respective
systems. This respects the native decision-making processes in those
systems and enables multi-party groups backing those systems to
interact with each other as units.
o Minimize trust in gateways: the integrity of the protocol should not
be dependent on the reliability of either gateway. The next sub
section elaborates on the desired security properties.
o Preserving system autonomy and self-sovereignty: the endpoint systems
should have complete freedom in determining their respective access
controls and verification policies, and in choosing when to initiate a
view request or whether to respond to a view request. The internal
activities of each system should be oblivious to the other and should
not affect data sharing protocol instance.
o Accommodating heterogeneity: the end-to-end protocol should work the
same regardless of the distributed ledger technology implementation
backing either endpoint system.
o Avoid synchronization: the protocol should not rely on any externally
guided synchronization mechanism, such as a global clock, and instead
rely purely on asynchronous message transfers.
5.9. Security Considerations
The security considerations of the protocol include, but are not limited
to, the following:
o Distributed consensus: rely on the consensus mechanism of the
counterparty system both to authenticate view requests and to validate
views. This can mitigate (or avoid) Byzantine failure of malicious
nodes within the endpoint systems. It can also prevent a malicious
client from supplying a fake view in the destination system.
o Integrity: rely on digital signatures over the view requests and
responses (made by the client in the destination system and peers in
the source system) so that the gateways cannot tamper with the
messages undetected.
o Confidentiality: rely on end-to-end encryption of the view response so
that the gateways cannot exfiltrate the view contents and/or the
associated proofs. Exfiltration will violate the access control
policies of the source system.
o Availability: rely on redundancy and failover to mitigate against
denial-of-service attacks mounted by either gateway. Multiple gateways
should be configured and kept on standby in practice.
5.10. Privacy Considerations
Access control policies allow source systems to have privacy by default,
and only reveal the minimum ledger information necessary to external
entities. Any data shared across two systems is private between them
only if the gateways are maintained by stakeholders within the respective
systems. This should be kept in mind when selecting or discovering
gateways for data sharing instances.
5.11. Fault Tolerance and Crash Recovery
The usual considerations of fault tolerance, crashes, and session
maintenance, apply to gateways involved in data sharing. Various
techniques for failover and session state and log backups can be used to
guard against, or recover from, the possibility of either gateway failing
during a data sharing instance. Details are beyond the scope of this
draft, which makes no recommendations on this topic either.
6. Pre-request setup and configuration
Either endpoint system in a data sharing protocol instance must have the
following configured in their respective data stores, which, if the
system is a distributed ledger system, should be a shared ledger.
o View request access control policies: as described in Section 8, one
or more access control policy rules according to the given
specification should be recorded before a data sharing protocol
instance. If a view request is received by a system and there is no
appropriate policy rule in the system’s record, the principle of least
privilege should be applied, and the view request rejected.
o View verification policies: as described in Section 6, one or more
verification policies according to the given specification should be
recorded before a data sharing protocol instance. If a view is
received by a system and there is no appropriate policy rule in the
system’s record, the view should be deemed invalid. The client itself
ought to avoid sending a view request if an appropriate verification
policy cannot be retrieved, but even if a malicious client proceeds
with a spurious view request, the destination system’s back end should
declare the proof accompanying the view response to be invalid.
o External identities and certifications: participating systems can be
abstracted into one or more security domains that represent the
stakeholders of that system. For effective policy enforcement, i.e.,
to authenticate a view request or validate a view, knowledge of a
remote system’s security domains—identity providers, certification
authorities, and group structure if the system is a distributed
ledger—is necessary. This information is typically, though not limited
to, a set of certificate hierarchies, which should be determined and
recorded to the system’s data store before a data sharing protocol
instance. In the absence of such recorded information about the
counterparty system, the protocol should terminate in the view request
access control check step or in the view validation step.
7. Related Open Issues
This draft provides a specification for views and how to addresses them.
It further describes a protocol whereby one system can request a view
from another through gateways. But there are several aspects of the end
to-end process, which are extraneous to the data sharing protocol yet
crucial to its successful completion. Though detailed specifications of
these are beyond the scope of this draft, we list them in this section
for readers’ considerations.
7.1. Global identification of blockchain systems and public keys
To construct a view address as well as determine a suitable gateway to
send a view request to, we need identifiers and naming systems for
distributed ledgers and the networks that maintain them. In addition, we
need ways to associate public keys with these names for authentication
purposes. Further, we need mechanisms to store and retrieve these
identifiers and keys in a distributed, and ideally decentralized, manner.
The concepts of Decentralized Identifiers [DID] and Self-Sovereign
Identity [SSI] are promising technologies to begin devising such
specifications.
7.2. Discovery of gateways nodes within a blockchain system
To initiate a data sharing protocol, a client in a distributed ledger
system needs to identify a suitable gateway node. This can be done in
several different ways, one of which involves registering the set of
gateways on a shared ledger within the system. Because, ideally, the
gateway does not need to be highly trusted, there are few security
implications but potentially larger efficiency implications in the choice
of mechanism for registration and discovery of local gateway nodes.
7.3. Remote gateway discovery
How gateways can discover other gateways acting on behalf of remote
distributed ledger systems is an open question. The problem can be
related to the routing problem (i.e., discovery of routing paths) in
packet networking [RFC791].
7.4. Decentralized identity management across distributed ledger systems
Mechanisms are required to continuously sync external identities and
certifications as described in Section 10 as a basis for data sharing.
To keep these mechanisms are decentralized as possible and leverage
existing identity registries, we can leverage the concepts of
decentralized identifiers [DID] and verifiable credentials [VC22].
Protocols for this purpose, which use DID registries and trust anchors,
have been proposed [WRFCDID], and we can use them as
starting points for this specification.
8. References
8.1. Normative References
[DID] Sporny, M., Longley, D., Sabadello, M., Reed, D., Steele, O.,
and C. Allen, "Decentralized Identifiers (DIDs) v1.0, W3C
Recommendation", July 2022, <https://w3c.github.io/did-core/>.
[FATF] FATF, "International Standards on Combating Money
Laundering and the Financing of Terrorism and
Proliferation - FATF Revision of Recommendation 15",
October 2018, <http://www.fatf-
gafi.org/publications/fatfrecommendations/documents/fatf-
recommendations.html>.
[ISO] ISO, "Blockchain and distributed ledger technologies-
Vocabulary (ISO:22739:2020)", July 2020,
<https://www.iso.org>.
[NIST] Yaga, D., Mell, P., Roby, N., and K. Scarfone, "NIST
Blockchain Technology Overview (NISTR-8202)", October
2018, <https://doi.org/10.6028/NIST.IR.8202>.
[RFC791] Information Sciences Institute, University of Southern
California, "Internet Protocol, DARPA Internet Program,
Protocol Specification, IETF RFC 791", September 1981,
<https://datatracker.ietf.org/doc/html/rfc791>.
[SATA] Hardjono, T., Hargreaves, M., Smith, N., and V. Ramakrishna,
"Secure Asset Transfer (SAT) Interoperability Architecture,
IETF, draft-ietf-satp-architecture-02.", January 2024,
<https://datatracker.ietf.org/doc/draft-ietf-satp-
architecture/>.
[SATP] Hargreaves, M., Hardjono, T., and R. Belchior,
"Secure Asset Transfer Protocol (SATP), IETF,
draft-ietf-satp-core-02.", July 2023,
<https://datatracker.ietf.org/doc/draft-ietf-satp-core/>.
[SATU] Ramakrishna, V., and T. Hardjono, "Secure Asset Transfer (SAT)
Use Cases, IETF, draft-ietf-satp-usecases-01.", July 2023,
<https://datatracker.ietf.org/doc/draft-ietf-satp-usecases/>.
[SATV] Ramakrishna, V., Pandit, V., Abebe, E., Nishad, S., and K.
Narayanam, "Views and View Addresses for Secure Asset
Transfer, IETF, draft-ramakrishna-satp-views-addresses-02.",
January 2024, <https://datatracker.ietf.org/doc/draft-
ramakrishna-satp-views-addresses/>.
[SSI] Tobin, A., and D. Reed, "The Inevitable Rise of Self-Sovereign
Identity, A white paper from the Sovrin Foundation",
March 2017, <https://sovrin.org/wp-content/uploads/2018/03/
The-Inevitable-Rise-of-Self-Sovereign-Identity.pdf>.
[VC22] Sporny, M., Longley, D., and D. Chadwick, "Verifiable
Credentials Data Model v2.0, W3C Editor’s Draft", August 2022,
<https://w3c.github.io/vc-data-model/>.
8.2. Informative References
[ABCH20] Ankenbrand, T., Bieri, D., Cortivo, R., Hoehener, J., and
T. Hardjono, "Proposal for a Comprehensive Crypto Asset
Taxonomy", May 2020, <https://arxiv.org/abs/2007.11877>.
[BVGC20] Belchior, R., Vasconcelos, A., Guerreiro, S., and M.
Correia, "A Survey on Blockchain Interoperability: Past,
Present, and Future Trends", May 2020,
<https://arxiv.org/abs/2005.14282v2>.
[Clar88] Clark, D., "The Design Philosophy of the DARPA Internet
Protocols, ACM Computer Communication Review, Proc SIGCOMM
88, vol. 18, no. 4, pp. 106-114", August 1988.
[Ethe22] "Ethereum Whitepaper", September 2022,
<https://ethereum.org/en/whitepaper/>.
[Gray81] Gray, J., "The Transaction Concept: Virtues and
Limitations, in VLDB Proceedings of the 7th International
Conference, Cannes, France, September 1981, pp. 144-154",
September 1981.
[Herl19] Herlihy, M., "Blockchains From a Distributed Computing
Perspective, Communications of the ACM, vol. 62, no. 2,
pp. 78-85", February 2019,
<https://doi.org/10.1145/3209623>.
[HLP19] Hardjono, T., Lipton, A., and A. Pentland, "Towards and
Interoperability Architecture for Blockchain Autonomous
Systems, IEEE Transactions on Engineering Management",
June 2019, <https://doi:10.1109/TEM.2019.2920154>.
[HS2019] Hardjono, T. and N. Smith, "Decentralized Trusted
Computing Base for Blockchain Infrastructure Security,
Frontiers Journal, Special Issue on Blockchain Technology,
Vol. 2, No. 24", December 2019,
<https://doi.org/10.3389/fbloc.2019.00024>.
[IDevID] Richardson, M. and J. Yang, "A Taxonomy of operational
security of manufacturer installed keys and anchors. IETF
draft-richardson-t2trg-idevid-considerations-01", August
2020, <https://tools.ietf.org/html/draft-richardson-t2trg-
idevid-considerations-01>.
[SRC84] Saltzer, J., Reed, D., and D. Clark, "End-to-End Arguments
in System Design, ACM Transactions on Computer Systems,
vol. 2, no. 4, pp. 277-288", November 1984.
[WRFCDID] Ramakrishna, V., Narayanam, K., Chandra Ghosh, B.,
and E. Abebe, "Decentralized Network-Identity Discovery and
Management for Interoperation, Hyperledger Labs, Weaver: DLT
Interoperability, RFC 01-011", August 2022,
<https://github.com/hyperledger-labs/weaver-dlt-
interoperability/blob/main/rfcs/models/identity/network-
identity-management.md>.
Contributors
The authors would like to thank Krishnasuri Narayanam of IBM Research,
India, for discussing and brainstorming the ideas and specifications
presented in this draft, and subsequently reviewing this draft and
providing constructive suggestions for its improvement.
draft and providing constructive suggestions for its improvement.
Authors' Addresses
Venkatraman Ramakrishna
IBM Research,
Bangalore, India
Email: vramakr2@in.ibm.com
Vinayaka Pandit
IBM Research
Bangalore, India
Email: pvinayak@in.ibm.com
Ermyas Abebe
Consensys
Melbourne, Australia
Email: ermyas.abebe@consensys.net
Sandeep Nishad
IBM Research
Bangalore, India
Email: sandeep.nishad1@ibm.com
Dhinakaran Vinayagamurthy
IBM Research
Bangalore, India
Email: dvinaya1@in.ibm.com