Why is DARPA interested in secure messaging platform using blockchain technology?

Question

DARPA (US Defense Advanced Research Projects Agency) has released a Request for Proposal for a Secure Messaging Platform using a blockchain framework.

The following is the Objective paragraph from DARPA's call for proposal:

OBJECTIVE: Create a secure messaging and transaction platform that separates the message creation, from the transfer (transport) and reception of the message using a decentralized messaging backbone to allow anyone anywhere the ability to send a secure message or conduct other transactions across multiple channels traceable in a decentralized ledger.

The request for proposal is available in full, here: DARPA Call for Proposal for Secure Messaging Platform.

• Why are contemporary secure messaging platforms like TextSecure, Cryptocat, XMPP/OTR, Bitmessaging and so many more NOT enough?
  • What do these contemporary solutions lack, as the Secure Messaging Scorecard suggests many applications have all these features?
• What does blockchain provide when it comes to Secure Messaging and why it is necessary?

In particular, this paragraph of the proposal is not making sense to me

The messaging platform would act as the transport for a cyptographically sound record of all transactions whether they be MIPRs, contracts, troop movements or intelligence. Troops on the ground in denied communications environments would have a way to securely communicate back to HQ and DoD back office executives could rest assured that their logistics system is efficient, timely and safe from hackers. The benefits are broad and could even be applied to domains such as space. With crowded skies it’s important to maintain situational awareness of all satellites and those concerned with space situational awareness/telemetry or air traffic control could instantly share data between nations using a separate but equivalent ledger implementation thus removing questions as to the authenticity and integrity of the data.

What does transport mean here? How does blockchain help troops communicate in denied communication environment help? I am also not clear about the argument on situational awareness of satellites and how does blockchain enable sharing data between nations.

Simple answers would really help me and others like me. Thanks

Answer 1

I see your question as having two parts:

Why blockchain?

According to ZDNet's summary of the request, the preference for a decentralised blockchain solution is rooted in an interest in moving away from legacy centralised architectures, which DARPA describes as "expensive, inefficient, brittle and subject to cyber attack" at the given link.

Why not an existing solution?

From my view, DARPA's request for proposal is justified before even assessing the advantages of using a blockchain solution in particular.

After reading the summary by ZDNet, two reasons come to mind:

• Specialised requirements: The alternatives you list are for text (and basic attachments) only. By comparison, the linked article refers to planned use for Military Interdepartmental Purchase Requests (MIPR), described here in Oracle documentation. Verging towards a procurement solution, this requirement alone is beyond the capability of what you have listed. Also, without significant redesign, those solutions would not be capable of catering to military user groups and access levels.
• Dependency on third parties: More generally, it makes sense for any defense organisation to own the lifecycle of such a critical platform. Hypothetically, if the listed solutions did meet DARPA's requirements, to rely on an existing third-party solution would introduce unnecessary risk (e.g. non-DoD users on the platform, limited or no authority over design decisions, existing solution architecture being unlikely to meet defense standards). Although it is unfeasible to reinvent every technical solution in-house, in this example, little would be saved by relying on the listed alternatives.

Answer 2

It's DARPA, It's an experiment.

I agree that some of the concepts in the proposal are not suitable to current blockchain technology. For example "communicating in a constrained environment" may never be possible. This should not stop asking the question.

I expect they will quickly find the limitations and then start to workaround the problem. Make a hybrid technology. Maybe stay away from the tactical edge. Maybe focus on business, intel or healthcare systems. Too early to tell.

The DoD is under constant cyber threat. The defense is layered. This can add a layer. If the result is protecting strategic or mid level tactical data from viewing or tampering, then the added cost may be worth it. If it's just to protect a MIPR, well the benefits are probably negligible.

Answer 3

Only the people inside DARPA can tell you exactly why they're interested in such technology, but there are a few guesses we can make, based on the unique advantages that blockchain have that normal encrypted messaging doesn't have.

1. blockchain messaging allows recipient to cryptographically verify that it is not missing any messages, even if the recipient have spotty connection to the messaging network.
2. blockchain messages are traceable and tamper resistant. Once someone inserted the message into the chain and the block is verified by a number of participants, the message is part of the chain's permanent history. Some existing messaging system which are intended for anonymity intentionally delete old messages.
3. blockchain allows the participants to cryptographically verify the order that the communication happens, i.e. when A sends a message M to B, B can verify that A have received all messages prior to M when composing M.
4. blockchain can be synchronized through gossip rather than by a central server. Instead of depending on being able to communicate to central command, messages can spread through the network by syncing the blockchain through semitrusted/untrusted peers which cannot read messages that's not intended for them. This may be useful if your opponent have the ability to shut down the internet.
5. decentralized network have no single point of failure. If your centralized messaging server is nuked, you don't want your operatives to stop being able to communicate with each other.
6. bitmessage uses proof-of-work, which is probably unnecessary on military communication context

The ZDNet article from @Robyn's answer also talk about the requirements for "one time eyes only messages", which runs counter to block chain, which is supposed to be censorship resistant, instead of censoring the message after first view. It's possible that this is just another moonshot which DARPA is well known for.