fiftyone_pipeline_did

Strongly typed Python reader for the 51Did (51Degrees Identifier) returned by the 51Degrees Cloud service. Mirrors the .NET FiftyOne.Did package.

Terminology

• The 51Did (51Degrees Identifier) is the identifier as a whole.
• The envelope is the data model that carries it: a signed OWID holding the version, domain, date, payload and signature. It changes byte-for-byte every time the cloud issues one.
• The value is the stable, comparable part of the payload after the Flags and License Id: a 32-byte SHA-256 for Probabilistic and HashedEmail identifiers, or 16 GUID bytes for Random.

Comparing two 51Dids means comparing their values, never their envelopes.

Payload layout

Identifiers issued before the type tag existed have bits 6-7 zeroed and decode as PROBABILISTIC.

OWID dependency

FodId builds on the OWID envelope library (SWAN-community/owid-python, package owid), consumed via the 51Degrees/owid-python fork (git submodule; switch to upstream once published). Owid is composed, not subclassed: FodId holds an Owid and delegates OWID-level concerns to it.

Usage

from fiftyone_pipeline_did import FodId, IdType

fod_id = FodId.from_base64(base64_from_cloud_service)

flags = fod_id.flags
type_ = fod_id.type          # IdType.PROBABILISTIC / RANDOM / HASHED_EMAIL
license_id = fod_id.license_id
value = fod_id.hash          # SHA-256 or GUID bytes, see type

# Delegated OWID-level fields and operations.
domain = fod_id.domain
verified = fod_id.verify(public_key_pem)
base64 = fod_id.as_base64()

Comparing two 51Dids

a = FodId.from_base64(idprobglobal_a)
b = FodId.from_base64(idprobglobal_b)

# The envelope (date, signature, base64) differs across reissues.
# The value inside the payload is stable - this is what you compare:
same_value = a.hash == b.hash

Non-goals

• No signature verification on construction. Call verify(public_key_pem) when needed.
• No creation of new 51Dids. This is a parser; new 51Dids are issued by the 51Degrees cloud / on-premise hashing engines.