Any door can be secured with an onchain smart lock.

True: the evidence shows that essentially any door can be fitted with an onchain-controlled smart lock, for example through retrofit locks that fit standard doors. Mostly true: almost all ordinary doors can be, with only minor exceptions. Mixed: many doors can be, but substantial categories cannot (for example some fire doors or high-security doors). Mostly false: only specific door types support it, so "any door" is a large overstatement. False: onchain smart locks are not feasible for securing doors at all.

Set before the research began.

1. E1 Introducing Salto DLok — the next-generation, universal smart home lock built for every door. | Salto Salto Systems · 3 December 2025

   “The DLok is compatible with virtually any door type and allows for installation or retrofit in less than 15 minutes.”

2. E2 Retrofit vs Replacement Smart Locks Sensor and Latch · 19 August 2026

   “Retrofits are designed for standard single-cylinder deadbolts with a rotating thumbturn. A double-cylinder deadbolt keyed on both sides, a mortice lock, a multipoint lock on a patio door, or anything European-profile is a different mechanism and generally not supported.”

3. E3 Best Smart Locks for Existing Deadbolt Best Buy Canada · 10 August 2026

   “Many retrofit smart locks are designed for single-cylinder deadbolts, which have a keyhole outside and a thumb turn inside. Mortise locks, interconnected locks and double-cylinder deadbolts may not be compatible.”

4. E4 [PDF] IRONMONGERY AND SECURITY GAI SPECIFIER'S GUIDE Guild of Architectural Ironmongers (GAI) · September 2023

   “The 2003 version is harmonised/designated standard meaning locks must be CE/UKCA marked to this version of the standard when used on fire doors.”

5. E5 GAI Specifier's Guide: Ironmongery and Security Guild of Architectural Ironmongers (GAI) · September 2023

   “A multi-point locking system bolts the door into the frame and locks at multiple points at the turn of a key, giving a high level of security. They can also be electrically controlled by motor-driven latch bolt retraction thus allowing access control.”

6. E6 GAI Specifier's Guide: Ironmongery and Security Guild of Architectural Ironmongers (GAI) · September 2023

   “Whilst identical sets can be installed on other doors within a site, there is no direct interface or connection between this door and any other or to a computer system for transfer of data.”

7. E7 GAI Specifier's Guide: Ironmongery and Security Guild of Architectural Ironmongers (GAI) · September 2023

   “The 2003 version is harmonised/designated standard meaning locks must be CE/UKCA marked to this version of the standard when used on fire doors.”

8. E8 GAI Specifier's Guide: Ironmongery and Security Guild of Architectural Ironmongers (GAI) · September 2023

   “A lock designed for use on an internal domestic door will not stand up to use in a school or hospital.”

9. E9 Will a Smart Lock Fit Your Door? Complete Compatibility Guide SlockHub · 27 January 2024

   “Most replacement smart deadbolts are built for a standard cylindrical deadbolt, not every lock body. Mortise locks, multi-point doors, Euro cylinders, narrow stile doors, thick metal doors, glass near the lock, and older small-bore doors need extra checking before purchase.”

10. E10 Will a Smart Lock Fit Your Door? Complete Compatibility Guide SlockHub · 27 January 2024

    “Metal doors, fire-rated doors, commercial doors, and doors with glass near the lock deserve extra care. Drilling may require better tools, fire labels may restrict hardware changes, and glass can create security or clearance issues.”

11. E11 Electric Locking: Which is the right solution for the application? Article #3 - Performance standards for hardware ABLOY (ASSA ABLOY Group) · 3 February 2023

    “Therefore, any hardware or electric locking solution fitted to a fire door must be undertaken with care and due diligence must be shown to ensure that the modification will not reduce the integrity of the door with regards to its fire performance.”

12. E12 Slock.it - Knowledge4Policy (K4P) - European Commission European Commission, Knowledge4Policy (JRC/DG CONNECT #DLT4Good scanning) · 14 July 2020

    “Using blockchain technology, we help the Internet of Things (IoT) environment in its technological foundation by providing the IoT layer to power secure and interoperable transactions between machines and humans and by enabling the economy of things.”

The independent sources say retrofit smart locks are mainly built for standard single-cylinder deadbolts. Mortise, multipoint, double-cylinder and Euro-profile locks are generally not supported or need extra checking (E2, E3, E9). Locks used on fire doors must be marked to a set standard, fitting hardware to fire doors needs care, and fire labels may restrict hardware changes (E7, E10, E11). That suggests "any door" overstates what ordinary smart locks can do. However, none of the evidence shows that onchain-controlled locks exist or work on any door: E1 describes a smart lock without mentioning onchain control, and E12 does not mention locks or doors. So the evidence cannot tell apart the "mixed", "mostly false" and "false" outcomes the criteria describe.