Sample Guardianship Trust Framework¶

This document describes a sample trust framework for guardianship appropriate to the IRC-as-guardian-of-Mya-in-a-refugee-camp use case. It is accompanied by a sample schema for a guardian credential.

For general background on guardianship and its associated credentials, see this slide presentation.

The trust framework shown here is a reasonable starting point, and it demonstrates the breadth of issues well. However, it probably would need significantly more depth to provide enough guidance for developers writing production software, and to be legally robust in many different jurisdictions.

Name, Version, Author¶

This is the "Sovrin ID4All Vulnerable Populations Guardianship Trust Framework", version "1.0". The trust framework is abbreviated in credential names and elsewhere as "SIVPGTF". It is maintained by the Sovrin ID4All Working Group. Credentials using the schema described here are known as gcreds.

Scope¶

The trust framework applies to situations where NGOs like the International Red Cross/Red Crescent, UNICEF, or Doctors Without Borders are servicing large populations of vulnerable refugees, both children and adults, in formal camps. It assumes that the camps have at least modest, intermittent access to telecommunications, and that that they operate with at least tacit approval from relevant legal authorities. It may not provide enough guidance or protections in situations involving active combat, or in legal jurisdictions where rule of law is very tenuous.

Rationales for Guardianship¶

In this framework, guardianship is based on one or more of the following formally defined rationales:

dependent-appointment: The dependent was capable of appointing a guardian, and chose to appoint the named guardian(s) to that role. This is considered the strongest rationale for guardianship.
kinship: The dependent is known to be vulnerable because of age or disability. The guardian is related to the dependent and thus has a natural claim to guardianship status. This trust framework formally recognizes the following kinship relationships, in order from strongest to weakest: biological-parent, step-parent, sibling, grandparent, aunt-or-uncle, first-cousin, indirect-relative, tribe-adult. Kinships weaker than first-cousin are considered invalid as the rationale for guardianship by themselves.
adjudicated: A legal authority, or a council consisting of 5 grandmothers, chose the guardian.
self: No suitable guardian could be found on another basis, but the dependent needed a guardian, so the guardian assumed the status until a better alternative could be found.

Identifying a guardian¶

This framework assumes that credentials will use ZKP technology. Thus, no holder attributes are embedded in a gcred except for the holder's blinded link secret. During a guardian challenge, the holder should include appropriate identifying evidence based on ZKP credential linking.

Identifying a dependent¶

This framework defines the following formal ways to identify a dependent in a gcred:

credentialSubject.first_name
credentialSubject.last_name
credentialSubject.birth_date
credentialSubject.gender
credentialSubject.native_language
credentialSubject.identifying_marks
credentialSubject.photo
credentialSubject.iris
credentialSubject.fingerprint

These fields should appear in all gcreds. First name should be the name that the dependent acknowledges and answers to, not necessarily the legal first name. Last name may be empty if it is unknown. Birth date may be approximate. Photo is required and must be a color photo of at least 800x800 pixel resolution, taken at the time the guardian credential is issued, showing the dependent only, in good light. At least one of iris and fingerprint are strongly recommended, but neither is required.

Permissions¶

Guardians may be assigned some or all of the following formally defined permissions in this trust framework:

routine-medical-care: Consent to normal medical treatment, including vaccinations, HIV tests, prescriptions, hospitalization, dental procedures, surgeries, and so forth.
do-not-resuscitate: Consent to discontinue life support.
school: Enroll or unenroll dependent in school programs. Customize courses of instruction.
necessaries: Receive food, hygiene items, clothing, and other materials allocated to the dependent.
gender-identity: Specify the gender by which the dependent shall be known.
religious-observance: Require the dependent to observe religious practices, or consent for the dependent not to do so.
light-travel: Take the dependent outside the camp, returning before dark.
extended-travel: Take the dependent outside the camp for extended periods.
unenroll: Permanently remove the dependent from the camp's care.
contracts: Enter into financial or other legally binding arrangements on behalf of the dependent.
marriage-family-planning: Give consent for the dependent to marry, or require them to do so. Direct the use contraceptives.
delegate: Give permission to a non-guardian to exercise some of the guardian's privileges, possibly with restrictions.
successor: Designate a replacement to assume guardian duties.
authorize: Configure the permissions of self or other guardians.

Constraints¶

A guardian's ability to control the dependent may be constrained in the following formal ways by guardian credentials that use this trust framework:

Boundary¶

Guardian can only operate within named boundaries, such as the boundaries of a country, province, city, military command, river, etc. Boundaries are specified as a localized, comma-separated list of strings, where each locale section begins with a | (pipe) character followed by an ISO639 language code followed by a : (colon) character, followed by data. All localized values must describe the same constraints; if one locale's description is more permissive than another's, the most restrictive interpretation must be used. An example might be:

"constraints.boundaries": "|en: West side of Euphrates river, within Baghdad city limits
    |es: lado oeste del río Eufrates, dentro del centro de Bagdad
    |fr: côté ouest de l'Euphrate, dans les limites de la ville de Bagdad
    |ar: الجانب الغربي من نهر الفرات ، داخل حدود مدينة بغداد"

Point of Origin and Radius¶

The constraints.point_of_origin and radius fields are an additional or alternative way to specify a geographical constraint. They must be used together. Point of origin is a string that may use latitude/longitude notation (e.g., "@40.4043328,-111.7761829,15z"), or a landmark. Landmarks must be localized as described previously. Radius is an integer measured in kilometers.

"constraints.point_of_origin": "|en: Red Crescent Sunrise Camp"
"constraints.radius_km": 10

Jurisdictions¶

This is a comma-separated list of legal jurisdictions where the guardianship applies. It is also localized:

"constraints.jurisdictions": "|en: EU, India, Bangladesh"

Trigger and Circumstances¶

These are human-friendly description of circumstances that must apply in order to make the guardian's status active. It may be used in conjunction with a trigger (see next). It is vital that the wording of these fields be carefully chosen to minimize ambiguity; carelessness could invite abuse. Note that each of these fields could be used separately. A trigger by itself would unconditionally confer guardianship status; circumstances without a trigger would require re-evaluation with every guardianship challenge and might be used as long as an adult is unconscious or diagnosed with dementia, or while traveling with a child, for example.

"constraints.trigger": "|en: Death of parent"
"constraints.circumstances": "|en: While a parent or adult sibling is unavailable, and no
    new guardian has been adjudicated.
    |ar: في حين أن أحد الوالدين أو الأشقاء البالغين غير متوفر ، وليس
                  الوصي الجديد تم الفصل فيه."

Timing¶

These allow calendar restrictions. Both start time and end time are expressed as ISO8601 timestamps in UTC timezone, but can be limited to day- instead of hour-and-minute-precision (in which case timezone is irrelevant). Start time is inclusive, whereas end time is exclusive (as soon as the date and time equals or exceeds end time, the guardianship becomes invalid). Either value can be used by itself, in addition to being used in combination.

"constraints.startTime": "2019-07-01T18:00"
"constraints.endTime": "2019-08-01"

Auditing¶

It is strongly recommended that an audit trail be produced any time a guardian performs any action on behalf of the dependent, except for school and necessaries. Reports of auditable events are accomplished by generating a JSON document in the following format:

{
    "@type": "SIVPGTF audit/1.0",
    "event_time": "2019-07-25T18:03:26",
    "event_place": "@40.4043328,-111.7761829,15z",
    "challenger": "amy.smith@redcross.org",
    "witness": "fred.jones@redcross.org",
    "guardian": "Farooq Abdul Sami",
    "rationale": "natural parent",
    "dependent": "Isabel Sami, DOB 2009-05-21",
    "event": "enroll in class, receive books",
    "justifying_permissions": "school, necessaries"
    "evidence": // base64-encoded photo of Farooq and Isabel
}

Appeal¶

NGO staff (who receive delegated authority from the NGO that acts as guardian), and a council of 5 grandmothers maintain a balance of powers. Decisions of either group may be appealed to the other. Conformant NGOs must identify a resource that can adjudicate an escalated appeal, and this resource must be independent in all respects--legal, financial, human, and otherwise--from the NGO. This resource must have contact information in the form of a phone number, web site, or email address, and the contact info must be provided in the guardian credential in the appeal_uri field.

Freshness and Offline Operation¶

[TODO]

Revocation¶

[TODO]

Best Practices¶

Perform a guardian challenge whenever a guardian attempts an action requiring permissions other than school and necessaries.
Require the disclosure of dependent photo and the comparison of the photo to the dependent, who must be physically present, for all operations using the routine-medical-care, do-not-resuscitate, gender-identity, and light-travel permissions.
Require a biometric match (fingerprint or iris strongly preferred, or else photo plus two related adult witnesses) for the extended travel, unenroll, contracts, and marriage-family-planning permissions to be exercised where possible.