Security Standards under Review for esMD

Transaction Timeline An esMD transaction begins with the creation of some type of electronic content (e.g. X12 274, 277, or 275 message or an HPD Plus DSML, CDA, or PDF document). As the content is packaged into a message and sent, security elements are added at points along the timeline dependent on the standard(s) selected and the purpose of the security element. This process is reversed on the receiving end. Electronic Content Created Content Stored as a document XD* Metadata Content packaged into payload Message created Message Sent DSG Signature X12 58 Signature WS- Security Encryption (transport level) CAQH CORE Metadata Internal SystemsGateway Message Received Process Header Process Payload X12 58 Signature WS- Security CAQH CORE/ XD* Metadata Process Content DSG Signature Internal Systems GatewayInternet Store Content

IHE DSG The Document Digital Signature (DSG) content profile specifies the use of XML Advanced Electronic Signatures (XAdES) for documents that are shared between organizations. Process Flow for Phase 1 Sending Medical Documentation Transaction Structure

Extensions to Metadata This approach would extend existing metadata to support the exchange of the required security information. For esMD, this would require extensions to CAQH CORE and XD* metadata. We would need to work with the relevant organizations to seek inclusion of these changes in future specifications. Process Flow for UC1 Registration Transaction Structure

X12 58 This standard defines the data formats for authentication, encryption, and assurances in order to provide integrity, confidentiality, and verification and non-repudiation of origin for two levels of exchange of EDI formatted data defined by ASC X12. Process Flow for UC1 Registration Transaction Structure

WS-Security This specification extends SOAP Messages to provide three main security capabilities: the ability to send security tokens as part of a message, message integrity, and message confidentiality. Process Flow for UC1 Registration Transaction Structure

esMD Security Requirements

Identity Requirements RequirementDescriptionRegistrationSend eMDR Send eMD Include Sender's public digital certificate in transaction - Receiver traces certificate to root CA in order to verify sender's identity. - Receiver uses public key and digital signature to verify authenticity. yyy Include additional public digital certificates in transaction - Transaction includes public digital certificates of all other parties that have digitally signed something in the transaction. - Receiver traces certificates to root CAs in order to verify identity of all parties that have digitally signed something in the transaction. - Receiver uses public keys and digital signatures to verify authenticity of all parties that have digitally signed something in the transaction. - Receiver uses certificates to verify all delegation of rights artifacts created by all parties that have digitally signed an assertion yny

Authenticity Requirements 1/2 RequirementDescriptionRegistrationSend eMDR Send eMD Digital Signature of portion of transaction (message) - All parties that interact with transaction can sign it - Receiver uses digital signature to verify authenticity of message across all hops nnn Digital Signature of entire transaction (message) - Sender of message can sign it - Receiver uses digital signature to verify authenticity of message yyy Digital Signature of a contributor to a document (payload) - Multiple content creators sign relevant portions of payload - Receiver uses digital signatures to verify authenticity of content nnLevel 1 - n Level 3 - y Digital Signature of an entire document (payload) - Single content creator signs entire payload - Receiver uses digital signatures to verify authenticity of content nnLevel 1 - n Level 2 - y Digital Signature of an aggregation of documents (payload) - Single content creator signs entire payload - Receiver uses digital signatures to verify authenticity of content nnLevel1 - y

Authenticity Requirements 2/2 RequirementDescriptionRegistrationSend eMDR Send eMD Supports digital signature chains - Receiver understands the order in which digital signatures were applied - Receiver understand what part of the transaction each digital signature applies to yny Supports long term validation of digital signatures - Receiver can validate digital signature up to twenty years after signing - Example: Content creator adds time-stamped and CA signed OCSP response or CRL to content at time of creation nny

Authority Requirements RequirementDescriptionRegistrationSend eMDR Send eMD Include single delegation of rights artifacts in transaction - Party A delegates a right to Party B who may not delegate that right to any other party nnn Include multiple delegation of rights artifacts in transaction - Party A delegates a right to Party B who may delegate that right to Party C yny

Encryption Requirements RequirementDescriptionRegistrationSend eMDR Send eMD Support encryption of components of payload at point of creation - Content creator encrypts portions of the payload nnLevel 1 - n Level 3 - ? Support encryption of entire payload at point of creation - Content creator encrypts entire payloadnnLevel 1 - n Level 2 - ? Note: esMD assumes transport level encryption is in place. Payload encryption is still under consideration

General Requirements CategoryRequirementDescriptionRegistrationSend eMDR Send eMD LocationSecurity elements are included in payload - Security elements are tied to payload and will be processed by internal systems rather than gateway y (Delegation of Rights) ny Existing Standard Created and maintained by SDO - Uses existing standardyyy Applicable Standard X Supports the exchange of provider information ynn Applicable Standard IHE HPD+- Supports the exchange of provider information ynn Applicable Standard X Supports the exchange of requests for additional information regarding a claim nyn Applicable Standard X Supports the exchange of additional information regarding a claim nny Applicable Standard HL7 CDA- Supports the exchange of patient clinical information nny

esMD Security Requirements Aligned to Standards by Use Case

Use Case 1: Requirements for Registration CategoryRequirementDSGX12 58WS- Security Metadata Extensions IdentityInclude Sender's public digital certificate in transaction n?yy IdentityInclude additional public digital certificates in transaction y?yy AuthenticitySupports digital signature chains?2?yy Authenticity Digital Signature of entire transaction (message) nnyn AuthorityInclude multiple delegation of rights artifacts in transaction yn?y AuthoritySupports delegation of rights artifact chains?n?y Existing StandardCreated and maintained by SDO yyyn Applicable StandardX ?yyy Applicable StandardsIHE HPD+ ynyy Location Security requirements are included in payload yy?ny

Use Case 2: Requirements for Sending eMDRs CategoryRequirementDSGX12 58WS- Security Metadata Extensions IdentityInclude Sender's public digital certificate in transaction y?yy Authenticity Digital Signature of entire transaction (message) nnyn Existing StandardCreated and maintained by SDOyyyn Applicable StandardX12 277?yyy

Phase 1: Requirements for Sending Electronic Medical Documentation CategoryRequirementDSGX12 58WS- Security Metadata Extensions IdentityInclude Sender's public digital certificate in transaction y?yy IdentityInclude additional public digital certificates in transaction y?yy AuthenticitySupports digital signature chains??yy AuthenticitySupports long term validation of digital signature y?yy AuthenticityDigital Signature of entire transaction (message) nnyn AuthenticityDigital Signature of an aggregation of documents (payload) yy/n AuthorityInclude multiple delegation of rights artifacts in transaction yn?y AuthoritySupports delegation of rights artifact chains?n?y LocationSecurity elements are included in payload yynn Existing StandardCreated and maintained by SDO yyyn Applicable StandardX ?yyy Applicable StandardHL7 CDA ynyy

Conclusions No single standard/specification supports all requirements for all use cases Support for some requirements depends on implementation details Example: WS-Security can sign an entire message or a portion of a message, including the payload. However, this signature would usually be processed by the SOAP gateway and unavailable to the internal information systems. A mix of standards may be required, each one selected to fulfill a specific requirement

Comparison of Security Standards under Review for esMD

IHE DSG Strengths -Supports transmission of signatures and certificates -Based on XMLSig and XAdES which provides long-term validation of signatures -Can be used to sign any kind of document -XML transforms are not required -Signatures applied to payload and processed by internal system -Potentially meets AoR Level 2 requirements Weaknesses -Receiver must track both signed document and signature document -Applicability limited to signing of documents -Probably does not meet AoR Level 3 requirements

Extensions to Metadata Strengths -Potentially designed to meet exact needs of esMD -Signatures applied to payload and processed by internal system Weaknesses -Requires changes to existing standards -Relevant SDOs may choose to not adopt changes -Cannot sign entire SOAP message Alternatives -MIME Attachments: Attach various security artifact files to payload using appropriate MIME content-type

X12 58 Strengths -Standard across all X12 transactions -Applies signature at payload level Weaknesses -Only applicable to X12 transactions -Requires separate transaction to exchange certificates -Requires maintenance of certificates apart from transaction -No support for Delegation of Rights

WS-Security Strengths -Supports transmission of signatures and certificates -Easily supported in all SOAP based transactions -Based on XMLSig standard -Can support XAdES which provides long-term validation of signatures -Supports exchange of SAML Assertions (for Delegation of Rights) Weaknesses -Signatures are applied to message and processed at gateway -Gateway would require additional configuration to pass signatures, certificates, and SAML Assertions to internal system -No definitive specification binding SOAP over SMTP for Direct purposes Alternatives -S/MIME: Default signing and encryption of Direct messages

Security Approach 1 Message NwHIN/CORE: WS-Security to sign message and transmit certificate used to sign message Optional: Gateway passes security tokens to internal information system Direct: S/MIME to sign message and transmit certificate used to sign message Payload IHE DSG to sign document bundle NwHIN/CORE: ZIP file containing document bundle and signature document placed in 275 BIN segment Direct: ZIP file containing document bundle and signature document sent as attachment to payload Additional security elements sent as attachments to payload Delegation of Rights: Signed SAML Assertion file attached as MIME content-type text/xml Public Certificates: Certificate file (PEM, DER, PKCS12, PKCS7) attached as appropriate MIME content-type application/x-pkcs____ Strengths -Uses existing standards -Supports transmission of signatures and certificates -All signatures based on XMLSig standard -Supports XAdES signature on document bundle, which provides for long-term validation of signature -Supports exchange of SAML Assertions for Delegation of Rights -Gateway processes message signature -Internal system processes document bundle signature, delegation of rights artifact, and any additional certificates -Does not preclude use of X12 58 if required by trading partners Weaknesses -Combines multiple specifications instead of using single specification for all security requirements -Receiver must maintain attachments and track relationships between files -Approach is not completely transport neutral

esMD Transaction Process Flow by Use Case

Use Case 1: Transaction Process Flow Registration Request Delegation of Rights Artifact Signature of Registration Request Public Certificate of Registration Requestor Assertion of Rights Signature of Assertion Public Certificate of Assertor Delegation of Rights Artifact Registration Request Message OwnerProcessStandards Registration Requestor Request Delegation of Rights Artifact from Assertor of Rights SAML Query Assertor of Rights Create Assertion SAML Sign Assertion and attach certificate XMLSig Provide Delegation of Rights Artifact to Registration Requestor SAML Response Registration Requestor Create Registration Request Payload: X12.274, HPD Attach Delegation of Rights Artifact and attach Certificate of Subject Payload: MIME Attachment of Signed SAML Assertion Sign Registration Request Message and attach certificate NwHIN/CORE Message: WS- Security DIRECT Message: S/MIME Send Registration Request Message NwHIN/CORE Direct Payer/Payer Contractor Trace Certificate of Registration Requestor to Root CA NwHIN/CORE Message: WS- Security DIRECT Message: S/MIME Verify Signature of Registration Request NwHIN/CORE Message: WS- Security DIRECT Message: S/MIME Verify Delegation of Rights Artifact Payload: MIME Attachment of Signed SAML Assertion Process Registration Request Payload: X12.274, HPD

Use Case 2: Transaction Process Flow eMDR Message eMDR Signature of eMDR Public Certificate of Payer/Payer Contractor OwnerProcessStandards Payer/Payer Contractor Create eMDR Payload: X Sign eMDR Message and attach certificate NwHIN/CORE Message: WS- Security DIRECT Message: S/MIME Send eMDR Message NwHIN/CORE Direct eMDR Consumer Trace Certificate of Payer/Payer Contractor to Root CA NwHIN/CORE Message: WS- Security DIRECT Message: S/MIME Verify Signature of eMDR NwHIN/CORE Message: WS- Security DIRECT Message: S/MIME Process eMDR Payload: X12.277

Phase 1: Transaction Process Flow Signed Medical Document Bundle eMDR Response Message eMDR Response Document Bundle Attachment Signature of eMDR Response Public Certificate of eMDR Consumer Medical Document Bundle Signature of Document Bundle Public Certificate of Document Bundle Owner OwnerProcessPossible Locations and Standards EHR/Provider Assemble Medical Document Bundle Payload: PDF, CDA, ZIP Sign Document Bundle Payload: DSG Attach Public Certificate Payload: DSG Provide Medical Document Bundle Attachment to eMDR Consumer Outside esMD scope eMDR Consumer Create eMDR Response Payload: X12.275, XD* Add Document Bundle Attachment Payload: BIN Seg, Attachment Sign eMDR Response and attach certificate NwHIN/CORE Message: WS- Security DIRECT Message: S/MIME Send eMDR Response Message NwHIN/CORE Direct Payer/Payer Contractor Trace Certificate of eMDR Consumer to Root CA NwHIN/CORE Message: WS- Security DIRECT Message: S/MIME Verify Signature of eMDR Response NwHIN/CORE Message: WS- Security DIRECT Message: S/MIME Process eMDR Response Payload: X12.275, XD* Consume Document Bundle Payload: DSG

Appendix: Security Dataset Requirements for both Registering to Receive eMDRs & Sending eMDRs

Signature Artifact The Signature Artifact (paired with the Public Digital Certificate of the Sender) will enable the message receiver to authenticate the sender, verify message integrity, and prove non-repudiation. 1.Public Digital Certificate of Sender – x.509 certificate issued by a Certificate Authority 2.Signature Artifact – Encrypted hash of the message* * The exact details of the Signature Artifact are being developed in the esMD Author of Record Initiative.

Public Key of Dr. Smith Signature Artifact Example 1. Dr. Smith attaches signature artifact to Request to Register to Receive eMDRs Registration Request Provider Name: Dr. Smith NPI: Service: Receive eMDRs Metadata Encrypted Hash: H8K9QTP Public Digital Certificate of Dr. Smith checksum function Hash: signing algorithm Private Key of Dr. Smith 2. Payer verifies the Request came from Dr. Smith and has not been tampered with Registration Request Provider Name: Dr. Smith NPI: Service: Receive eMDRs Metadata Encrypted Hash: H8K9QTP Public Digital Certificate of Dr. Smith checksum function Hash: signing algorithm Verify Identity Hash: Verify Integrity

Delegation of Rights Artifact The Delegation of Rights Artifact (paired with the Public Digital Certificate of Subject) enables the Subject to delegate a right to the Sender of a Request such that the Receiver can cryptographically confirm that delegation of rights has occurred. 1.Public Digital Certificate of Subject – x.509 certificate issued by a Certificate Authority 2.Delegation of Rights Artifact – Encrypted hash of an assertion of rights* * The exact details of the Delegation of Rights Artifact are being developed in the esMD Author of Record Initiative.

Delegation of Rights Example (1/2) 1. Dr. Smith delegates the right to register his NPI to receive eMDRs to Medical Data, Inc. Registration Request Provider Name: Dr. Bob Smith NPI: Service: Receive eMDRs Metadata Encrypted Hash: H8K9QTP Public Digital Certificate of Medical Data, Inc. Delegation of Rights Artifact Public Digital Certificate of Dr. Smith 2. Medical Data, Inc. include their Signature Artifact, Dr. Smith’s Delegation of Rights Artifact, and both Public Digital Certificates in their Request to Register Dr. Smith to Receive eMDRs Assertion of Rights Dr. Bob Smith gives Medical Data, Inc. the right to register his NPI to receive eMDRs. Expiration Date: 1/1/2013 Metadata Encrypted Hash: U37G90P checksum function Hash: signing algorithm Private Key of Dr. Smith

Delegation of Rights Example (2/2) Registration Request Provider Name: Dr. Bob Smith NPI: Service: Receive eMDRs Metadata Encrypted Hash: H8K9QTP Public Digital Certificate of Medical Data, Inc. Delegation of Rights Artifact Public Digital Certificate of Dr. Smith 3. Payer verifies Medical Data, Inc. has the right to register Dr. Smith to receive eMDRs Public Key of Dr. Smith Assertion of Rights Dr. Bob Smith gives Medical Data, Inc. the right to register his NPI to receive eMDRs. Expiration Date: 1/1/2013 Metadata Encrypted Hash: U37G90P checksum function Hash: signing algorithm Hash: Verify Right