6.5 Resource AuditEvent - Content

6.5.1 Scope and Usage

The audit event is based on the IHE-ATNA Audit record definitions, originally from RFC 3881 , and now managed by DICOM (see DICOM Part 15 Annex A5 ).

• ASTM E2147 – Setup the concept of security audit logs for healthcare including accounting of disclosures
• IETF RFC 3881 – Defined the Information Model (IETF rule forced this to be informative)
• DICOM Audit Log Message – Made the information model Normative, defined Vocabulary, Transport Binding, and Schema
• IHE ATNA – Defines the grouping with secure transport and access controls; and defined specific audit log records for specific IHE transactions.
• NIST SP800-92 – Shows how to do audit log management and reporting – consistent with our model
• HL7 PASS – Defined an Audit Service with responsibilities and a query interface for reporting use
• ISO 27789 – Defined the subset of audit events that an EHR would need

This resource is managed collaboratively between HL7, DICOM, and IHE.

The primary purpose of this resource is the maintenance of security audit log information. However, it can also be used for any audit logging needs and simple event-based notification.

6.5.2 Background and Context

All actors; such as applications, processes, and services; involved in an auditable event should record an AuditEvent. This will likely result in multiple AuditEvent entries that show whether privacy and security safeguards, such as access control, are the properly functioning across an enterprise's system-of-systems. Thus it is typical to get an auditable event recorded by both the application in a workflow process, and the servers that support them. For this reason, duplicate entries are expected, which is helpful because it may aid in the detecting of, for example, fewer than expected actors being recorded in a multi-actor process or attributes related to those records being in conflict, which is an indication of a security problem. There may be non-participating actors that also detect a security relevant event and thus would record an AuditEvent, such as a trusted intermediary.

Security relevant events are not limited to communications or RESTful events. They include software startup and shutdown; user login and logout; access control decisions; configuration events; software installation; policy rules changes; and manipulation of data that exposes the data to users. See Audit Event Sub-Type vocabulary for guidance on some security relevant events.

The content of an AuditEvent is intended for use by Security System Administrators, Security and Privacy Information Managers, and Records Management personnel. This content is not intended to be accessible or used directly by other healthcare users, such as Providers or Patients, although reports generated from the raw data would be useful. An example is a Patient centric Accounting of Disclosures or an Access Report. Servers that provide support for Audit Event resources would not generally accept update or delete operations on the resources, as this would compromise the integrity of the audit record. Access of the AuditEvent would typically be limited to e.g., security, privacy, or other system administration purposes.

Relationship of AuditEvent and Provenance resources are often (though not exclusively) created by the application responding to the create/read/query/update/delete/execute etc. event. A Provenance resource resource contains overlapping information, but is a record-keeping assertion that gathers information about the context in which the information in a resource "came to be" in its current state, e.g., whether it was created de novo or obtained from another entity in whole, part, or by transformation. Provenance resources are prepared by the application that initiates the create/update of the resource, and may be persisted with the AuditEvent target resource.

6.5.2.1 Open Issues and Request for Comments

The AuditEvent Resource, like many of the FHIR Resources in DSTU, continues to be developed by the sponsoring HL7 Security Work Group. In particular, the Security WG continues to focus on refining the value sets used by both AuditEvent and its closely related Provenance Resource to ensure complete coverage of system and end user actions and action reasons that impact security objects (data, processes, applications, servers, etc.) The Security WG is particularly interested in implementer feedback on these focus areas, and at the same time cautions implementers to undertake due diligence in adapting these resources to their use cases.

At this juncture, there are multiple standard vocabularies in use that reflect different perspectives and levels of granularity on the concepts used to convey actions and reasons for actions. Both the AuditEvent and Provenance Resources are making available a number of those vocabularies via resource element bindings.

For example, AuditEvent has four elements that bind to "activity" vocabularies which could be used to convey the same concept where there’s no clear use case for doing so. E.g., a "read" action could be conveyed by AuditEvent.event.type, AuditEvent.event.subtype, AuditEvent.event.action, and AuditEvent.object.lifecycle. Only the AuditEvent.event.type is required, but is there a use case for including the others if the basic action is the same? However, there may be use cases in which both the high level CRUDE action value set is an important addition to a required code from AuditEvent.event.type. E.g., seems helpful where the required code = Audit event: Application Activity has taken place, and not so helpful if the required code = Audit Log has been used. The upshot is that implementers will need to carefully match the concepts in the value set bindings to their use cases to ensure that the level of granularity and concept selections are appropriate. The Security WG would appreciate comments on this, and in particular, how feasible or useful pre-coordination of these multiple activity value sets might be or whether collapsing these into one or two might be more appropriate.

The Security WG would also appreciate feedback from the implementer community on how well they are able to discern and utilize the different contexts in which the rationale for actions is conveyed using the HL7 Purpose of Use vocabulary [V:PurposeOfUse:2.16.840.1.113883.1.11.20448]. At this juncture, AuditEvent binds to this value set in four places:

• As Purpose of Event – where it’s a machine that is the audited agent
• As Purpose of Use – which is the Human User’s asserted POU
• As a Security Label Element – see 3rd Detailed Description below
• As a Security Label Metadata value Meta.security (Extensible)

The Security WG envisions use cases where these could be used in concert, but that would require system functionality that may not be feasible or beneficial to the implementer community. For example,

• Purpose of Event when the machine2machine is an EHR server and the user’s client supposedly being used for Treatment
• End User’s POU is Treatment and Research using e.g., DAF
• POU Security Label on the participant/target object of the AuditEvent = Legal, which is the POU for e.g., Legal Hold [i.e., no one but Records Management and Legal is supposed to have access but the Access Control System doesn’t do ABAC or the patient’s consent directive does not assent to POU = research, but the audited system has not implemented data segmentation to prevent End User from using the data to research
• Security Label on the AuditEvent Resource = System administration [because the only permitted use is for system administration/security]

Note that the binding of the value sets discussed above are currently set to extensible rather than example. Concerns have been raised about constraining vocabulary choices during DSTU especially for other jurisdictions. For example, outside of the US, ISO 13606 Purpose of Use codes are more likely used. Security WG would also appreciate feedback on whether these bindings should be example or extensible.

• Structure
• UML
• XML
• JSON
• All

<AuditEvent xmlns="http://hl7.org/fhir"> doco 
 <!-- from Resource: id, meta, implicitRules, and language -->
 <!-- from DomainResource: text, contained, extension, and modifierExtension -->
 <event> <!-- 1..1 What was done -->
 <type><!-- 1..1 Coding  Type/identifier of event  --></type>
 <subtype><!-- 0..* Coding  More specific type/id for the event  --></subtype>
 <action value="[code ]"/><!-- 0..1 Type of action performed during the event  -->
 <dateTime value="[instant ]"/><!-- 1..1 Time when the event occurred on source  -->
 <outcome value="[code ]"/><!-- 0..1 Whether the event succeeded or failed  -->
 <outcomeDesc value="[string ]"/><!-- 0..1 Description of the event outcome  -->
 <purposeOfEvent><!-- 0..* Coding  The purposeOfUse of the event  --></purposeOfEvent>
 </event>
 <participant> <!-- 1..* A person, a hardware device or software process -->
 <role><!-- 0..* CodeableConcept  User roles (e.g. local RBAC codes)  --></role>
 <reference><!-- 0..1 Reference(Practitioner|Organization|Device|Patient|
 RelatedPerson) Direct reference to resource  --></reference>
 <userId><!-- 0..1 Identifier  Unique identifier for the user  --></userId>
 <altId value="[string ]"/><!-- 0..1 Alternative User id e.g. authentication  -->
 <name value="[string ]"/><!-- 0..1 Human-meaningful name for the user  -->
 <requestor value="[boolean ]"/><!-- 1..1 Whether user is initiator  -->
 <location><!-- 0..1 Reference(Location) Where  --></location>
 <policy value="[uri ]"/><!-- 0..* Policy that authorized event  -->
 <media><!-- 0..1 Coding  Type of media  --></media>
 <network> <!-- 0..1 Logical network location for application activity -->
 <address value="[string ]"/><!-- 0..1 Identifier for the network access point of the user device  -->
 <type value="[code ]"/><!-- 0..1 The type of network access point  -->
 </network>
 <purposeOfUse><!-- 0..* Coding  Reason given for this user  --></purposeOfUse>
 </participant>
 <source> <!-- 1..1 Application systems and processes -->
 <site value="[string ]"/><!-- 0..1 Logical source location within the enterprise  -->
 <identifier><!-- 1..1 Identifier  The identity of source detecting the event  --></identifier>
 <type><!-- 0..* Coding  The type of source where event originated  --></type>
 </source>
 <object> <!-- 0..* Specific instances of data or objects that have been accessed -->
 <identifier><!-- 0..1 Identifier  Specific instance of object (e.g. versioned)  --></identifier>
 <reference><!-- 0..1 Reference(Any) Specific instance of resource (e.g. versioned)  --></reference>
 <type><!-- 0..1 Coding  Type of object involved  --></type>
 <role><!-- 0..1 Coding  What role the Object played  --></role>
 <lifecycle><!-- 0..1 Coding  Life-cycle stage for the object  --></lifecycle>
 <securityLabel><!-- 0..* Coding  Security labels applied to the object  --></securityLabel>
 <name value="[string ]"/><!-- ?? 0..1 Instance-specific descriptor for Object  -->
 <description value="[string ]"/><!-- 0..1 Descriptive text  -->
 <query value="[base64Binary ]"/><!-- ?? 0..1 Actual query for object  -->
 <detail> <!-- 0..* Additional Information about the Object -->
 <type value="[string ]"/><!-- 1..1 Name of the property  -->
 <value value="[base64Binary ]"/><!-- 1..1 Property value  -->
 </detail>
 </object>
</AuditEvent>

{doco 
 "resourceType" : "AuditEvent",
 // from Resource: id, meta, implicitRules, and language
 // from DomainResource: text, contained, extension, and modifierExtension
 "event" : { // R! What was done 
 "type" : { Coding  }, // R! Type/identifier of event 
 "subtype" : [{ Coding  }], // More specific type/id for the event 
 "action" : "<code >", // Type of action performed during the event 
 "dateTime" : "<instant >", // R! Time when the event occurred on source 
 "outcome" : "<code >", // Whether the event succeeded or failed 
 "outcomeDesc" : "<string >", // Description of the event outcome 
 "purposeOfEvent" : [{ Coding  }] // The purposeOfUse of the event 
 },
 "participant" : [{ // R! A person, a hardware device or software process 
 "role" : [{ CodeableConcept  }], // User roles (e.g. local RBAC codes) 
 "reference" : { Reference(Practitioner|Organization|Device|Patient|
 RelatedPerson) }, // Direct reference to resource 
 "userId" : { Identifier  }, // Unique identifier for the user 
 "altId" : "<string >", // Alternative User id e.g. authentication 
 "name" : "<string >", // Human-meaningful name for the user 
 "requestor" : <boolean >, // R! Whether user is initiator 
 "location" : { Reference(Location) }, // Where 
 "policy" : ["<uri >"], // Policy that authorized event 
 "media" : { Coding  }, // Type of media 
 "network" : { // Logical network location for application activity 
 "address" : "<string >", // Identifier for the network access point of the user device 
 "type" : "<code >" // The type of network access point 
 },
 "purposeOfUse" : [{ Coding  }] // Reason given for this user 
 }],
 "source" : { // R! Application systems and processes 
 "site" : "<string >", // Logical source location within the enterprise 
 "identifier" : { Identifier  }, // R! The identity of source detecting the event 
 "type" : [{ Coding  }] // The type of source where event originated 
 },
 "object" : [{ // Specific instances of data or objects that have been accessed 
 "identifier" : { Identifier  }, // Specific instance of object (e.g. versioned) 
 "reference" : { Reference(Any) }, // Specific instance of resource (e.g. versioned) 
 "type" : { Coding  }, // Type of object involved 
 "role" : { Coding  }, // What role the Object played 
 "lifecycle" : { Coding  }, // Life-cycle stage for the object 
 "securityLabel" : [{ Coding  }], // Security labels applied to the object 
 "name" : "<string >", // C? Instance-specific descriptor for Object 
 "description" : "<string >", // Descriptive text 
 "query" : "<base64Binary >", // C? Actual query for object 
 "detail" : [{ // Additional Information about the Object 
 "type" : "<string >", // R! Name of the property 
 "value" : "<base64Binary >" // R! Property value 
 }]
 }]
}

<AuditEvent xmlns="http://hl7.org/fhir"> doco 
 <!-- from Resource: id, meta, implicitRules, and language -->
 <!-- from DomainResource: text, contained, extension, and modifierExtension -->
 <event> <!-- 1..1 What was done -->
 <type><!-- 1..1 Coding  Type/identifier of event  --></type>
 <subtype><!-- 0..* Coding  More specific type/id for the event  --></subtype>
 <action value="[code ]"/><!-- 0..1 Type of action performed during the event  -->
 <dateTime value="[instant ]"/><!-- 1..1 Time when the event occurred on source  -->
 <outcome value="[code ]"/><!-- 0..1 Whether the event succeeded or failed  -->
 <outcomeDesc value="[string ]"/><!-- 0..1 Description of the event outcome  -->
 <purposeOfEvent><!-- 0..* Coding  The purposeOfUse of the event  --></purposeOfEvent>
 </event>
 <participant> <!-- 1..* A person, a hardware device or software process -->
 <role><!-- 0..* CodeableConcept  User roles (e.g. local RBAC codes)  --></role>
 <reference><!-- 0..1 Reference(Practitioner|Organization|Device|Patient|
 RelatedPerson) Direct reference to resource  --></reference>
 <userId><!-- 0..1 Identifier  Unique identifier for the user  --></userId>
 <altId value="[string ]"/><!-- 0..1 Alternative User id e.g. authentication  -->
 <name value="[string ]"/><!-- 0..1 Human-meaningful name for the user  -->
 <requestor value="[boolean ]"/><!-- 1..1 Whether user is initiator  -->
 <location><!-- 0..1 Reference(Location) Where  --></location>
 <policy value="[uri ]"/><!-- 0..* Policy that authorized event  -->
 <media><!-- 0..1 Coding  Type of media  --></media>
 <network> <!-- 0..1 Logical network location for application activity -->
 <address value="[string ]"/><!-- 0..1 Identifier for the network access point of the user device  -->
 <type value="[code ]"/><!-- 0..1 The type of network access point  -->
 </network>
 <purposeOfUse><!-- 0..* Coding  Reason given for this user  --></purposeOfUse>
 </participant>
 <source> <!-- 1..1 Application systems and processes -->
 <site value="[string ]"/><!-- 0..1 Logical source location within the enterprise  -->
 <identifier><!-- 1..1 Identifier  The identity of source detecting the event  --></identifier>
 <type><!-- 0..* Coding  The type of source where event originated  --></type>
 </source>
 <object> <!-- 0..* Specific instances of data or objects that have been accessed -->
 <identifier><!-- 0..1 Identifier  Specific instance of object (e.g. versioned)  --></identifier>
 <reference><!-- 0..1 Reference(Any) Specific instance of resource (e.g. versioned)  --></reference>
 <type><!-- 0..1 Coding  Type of object involved  --></type>
 <role><!-- 0..1 Coding  What role the Object played  --></role>
 <lifecycle><!-- 0..1 Coding  Life-cycle stage for the object  --></lifecycle>
 <securityLabel><!-- 0..* Coding  Security labels applied to the object  --></securityLabel>
 <name value="[string ]"/><!-- ?? 0..1 Instance-specific descriptor for Object  -->
 <description value="[string ]"/><!-- 0..1 Descriptive text  -->
 <query value="[base64Binary ]"/><!-- ?? 0..1 Actual query for object  -->
 <detail> <!-- 0..* Additional Information about the Object -->
 <type value="[string ]"/><!-- 1..1 Name of the property  -->
 <value value="[base64Binary ]"/><!-- 1..1 Property value  -->
 </detail>
 </object>
</AuditEvent>

{doco 
 "resourceType" : "AuditEvent",
 // from Resource: id, meta, implicitRules, and language
 // from DomainResource: text, contained, extension, and modifierExtension
 "event" : { // R! What was done 
 "type" : { Coding  }, // R! Type/identifier of event 
 "subtype" : [{ Coding  }], // More specific type/id for the event 
 "action" : "<code >", // Type of action performed during the event 
 "dateTime" : "<instant >", // R! Time when the event occurred on source 
 "outcome" : "<code >", // Whether the event succeeded or failed 
 "outcomeDesc" : "<string >", // Description of the event outcome 
 "purposeOfEvent" : [{ Coding  }] // The purposeOfUse of the event 
 },
 "participant" : [{ // R! A person, a hardware device or software process 
 "role" : [{ CodeableConcept  }], // User roles (e.g. local RBAC codes) 
 "reference" : { Reference(Practitioner|Organization|Device|Patient|
 RelatedPerson) }, // Direct reference to resource 
 "userId" : { Identifier  }, // Unique identifier for the user 
 "altId" : "<string >", // Alternative User id e.g. authentication 
 "name" : "<string >", // Human-meaningful name for the user 
 "requestor" : <boolean >, // R! Whether user is initiator 
 "location" : { Reference(Location) }, // Where 
 "policy" : ["<uri >"], // Policy that authorized event 
 "media" : { Coding  }, // Type of media 
 "network" : { // Logical network location for application activity 
 "address" : "<string >", // Identifier for the network access point of the user device 
 "type" : "<code >" // The type of network access point 
 },
 "purposeOfUse" : [{ Coding  }] // Reason given for this user 
 }],
 "source" : { // R! Application systems and processes 
 "site" : "<string >", // Logical source location within the enterprise 
 "identifier" : { Identifier  }, // R! The identity of source detecting the event 
 "type" : [{ Coding  }] // The type of source where event originated 
 },
 "object" : [{ // Specific instances of data or objects that have been accessed 
 "identifier" : { Identifier  }, // Specific instance of object (e.g. versioned) 
 "reference" : { Reference(Any) }, // Specific instance of resource (e.g. versioned) 
 "type" : { Coding  }, // Type of object involved 
 "role" : { Coding  }, // What role the Object played 
 "lifecycle" : { Coding  }, // Life-cycle stage for the object 
 "securityLabel" : [{ Coding  }], // Security labels applied to the object 
 "name" : "<string >", // C? Instance-specific descriptor for Object 
 "description" : "<string >", // Descriptive text 
 "query" : "<base64Binary >", // C? Actual query for object 
 "detail" : [{ // Additional Information about the Object 
 "type" : "<string >", // R! Name of the property 
 "value" : "<base64Binary >" // R! Property value 
 }]
 }]
}