lcmaas3 wrote on Saturday, July 06, 2013:
Hi all,
I will try to explain a little about Direct messaging to help clarify the hows and whys a bit.
First off, I want to be fully transparent to the OpenEMR community. I am a physician and also the CTO of EMR Direct, a small company whose main focus is Direct messaging. We work on both the EMR integration and technical side and the credentials and trust side of Direct messaging.
Several months ago, we contributed code to the OpenEMR project to provide a tie-in to our Direct messaging infrastructure so that OpenEMR users could easily enable Direct messaging for their providers (both send and receive) and for their patients through the patient portal (send only). All three of these are requirements for OpenEMR to achieve MU Stage 2 certification.
What is Direct?
At the simplest level, Direct messaging is a variation on S/MIME secure encrypted email. Every participant is issued a Direct Address (which looks just like an email address, but usually includes the word “direct” in the domain part somewhere). You will undoubtedly start to see these addresses show up in the provider community. These addresses can be issued to individual providers, clinics, hospitals or hospital departments, other healthcare related companies, and patients. People call it Direct messaging, Directed exchange, Direct Secure Messaging (DSM), but these all mean the same thing. The standard was developed by a volunteer workgroup known as the “Direct Project” under the guidance of ONC (the same folks that write the MU2 certification criteria).
Every Direct message is digitally signed by the sender to ensure its integrity (a built-in hash confirms that there were no erroneous changes while in transit) and ensure its authenticity (a recipient knows where the message came from by looking at the signature). The message is then encrypted for confidentiality and delivered to the recipient. Only the recipient can decrypt the message. Unlike HIE-style exchange, Direct is a “push” technology; there is no central repository of data.
How does it work?
Each Direct Address is tied to a digital credential, a specific type of X.509 security certificate, and each participant has a public key and private key for encryption/decryption and signing. So there is no need for pre-shared secrets or private networks. The public key lets other people communicate with you. The private key lets you (and only you) decrypt messages sent to you and digitally sign outgoing messages so your recipient can be confident about the source of the message. Since everyone is following the same standard, broad interoperability across vendors is possible.
What about trust?
The credential ties together a public key and an identity, so that others can be sure who they are communicating with. The “strength” of these credentials depends on who issues them. This gets to the trust concept that Brady mentions above. A Direct message is transmitted only when the sender and receiver have previously determined that they trust one another. Essentially, you get to decide with whom you will exchange messages, i.e. “who you trust”. This is not unlike your web browser trusting SSL certificates issued by certain companies and not others. Your web browser company or operating system company decided ahead of time which certificate issuers get an “OK” and which get the “warning untrusted site” message.
Where do you get credentials?
A participant can issue its own “self-signed” certificate or it can have one issued by a formal Certificate Authority, like EMR Direct. We participate in larger trust organizations with common standards, so our certificates are already trusted by numerous EHR vendors and health information exchange companies, including Cerner, ICA, Surescripts, Microsoft HealthVault, and many others. If you issue your own credentials, you will have to convince each party you want to exchange with to manually add your credential to their trust stores. In addition to immediate membership into our large multi-vendor trust communities, we also allow our users to add (“white-list”) any additional parties they need to communicate with.
Better than fax?
Yes. First off, fax is not digital; you get a scan of the document. With Direct, you get the original digital document. No smudgy lines, low resolution degradation, missing pages, etc. Color images, high-resolution EKG tracings, radiology snapshots, and more can be included. Second, Direct can carry the new common CCDA transition of care documents as a payload, so you can transmit a full summary of care to an ER, or receive discharge summaries from your local hospital, or a patient can use the patient portal to transmit their records efficiently without bothering your staff. Third, fax numbers get mis-dialed; it’s a fact. Fourth, the delivery confirmation options in Direct are more extensive that what you get with fax. Fifth, it’s required for MU2.
Why isn’t this a free service?
Our objective is to enable hiqh quality digital interoperability at the lowest cost. You might ask “why wouldn’t I just build it myself? It’s just S/MIME, right?” The biggest reasons are the ongoing care and feeding required to issue and manage certificates and operate a Direct messaging infrastructure. You have to meet minimum standards regarding collection and verification of identity documents and management/security of your credentials before most other Direct participants will exchange with you. And you will have to maintain a proper credential infrastructure (timely updating of Certificate revocation lists, renewals, etc.) to keep your Direct messaging services operational. To ensure interoperability across vendors, extensive cross-testing of the technology is required. To make sure you can communicate broadly with other physicians, patients, and hospitals, active management of trust relationships is necessary. We have spent a lot of time to make sure we do these things right.
I invite anyone with additional questions or with an interest in enabling Direct with OpenEMR to continue this thread or contact us directly at “support at emrdirect dot com”.
Luis Maas III, MD, PhD
CTO, EMR Direct
