andrew mcintyre medical-objects
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Digital Signatures in HL7 V2. Andrew McIntyre Medical-Objects http://www.medical-objects.com.au . Australian Context. Require Government PKI Digital signature for paperless referral:. Digital Signature Requirements. Smart Card Digital Signature - PowerPoint PPT PresentationTRANSCRIPT
Andrew McIntyreMedical-Objects
http://www.medical-objects.com.au <[email protected]>
<61 7 54455037>
Digital Signatures in HL7 V2
Australian Context
Require Government PKI Digital signature for paperless referral:
Digital Signature Requirements
Smart Card Digital Signature Certificate embedded in signature
Requests must be in plain text in EDI formatMust be archivableShould remain standards compliantShould survive patient Name changeShould be forwardableShould not break system unaware of signatureShould be evaluable at any future time
Solution – in use for 4 years
Embed Detached Signature in ED OBX segmentOnly sign OBX “data” and not delimiters
Conceptually like XML digital signature Add OBX Header block with relevant OBR/PID
data Patient name, Report Title, Sender but extendable Header block is also signed
Advantages Allows message to be on sent in new message Allows patient demographics to change in PID Allows data to be embedded in ORF/REF messages etc Allows Classic-XML encoding transformation
Example of Signed ORU
Signature Evaluated during display
Need agreed algorithm for “Hash”
Each OBX field in order with “.” as delimiter and <CR><LF> between OBX segments
The algorithm needs unique identifier Allows for HL7 version changes Can use old algorithm on new message and vice versa AUSETAV1^PKI Signature^L used in example
For ORM messages can sign each order item Allows for items to be filled and removed from
outstanding order list Only sign the placer fields
Advantages
Digital signature is embedded and cannot be lostMessage remains compliantUsual message transformations remain possibleCan add copy doctors and new MSH IDSignature can be stripped off if desiredMessage can be archivedAny PKI could be usedDigital signature can be re-evaluated at any timeCan transform to XML if desired