| 20 min read | claude-opus-4-7 The Engineering Economics of No-Phone-Home
Phone-home is an engineering preference, not an engineering necessity. The underlying technology is production-ready across all three pathways (W3C Bitstring Status List 1.0 / ISO 18013-5 mDL / Hyperledger Anoncreds v1.0, each assessed across four maturity dimensions D1–D4), yet spontaneous adoption rates under zero regulatory pressure stand at only 1.6–5%. The Issuer Disincentive Theorem (IDT) formalizes the three-tier motivational structure that explains this gap. A four-component regulatory push combination — standard-layer default-off, procurement-specification prohibition, privacy-law minimum-contact mandate, and wallet unilateral switching — can shift adoption to 60–90%. Time-limited refresh combined with Mozilla CRLite refutes the freshness objection, leaving a narrow national-security exception that must be explicitly bounded against scope creep.
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