In recent years, the use of smart locks and self check-in systems has also spread in Italy in accommodation facilities, from hotels to bed & breakfasts. These solutions offer guests autonomous and flexible access, eliminating the need for physical key delivery. However, like any IoT device applied to security, they bring with them new risks that traditional mechanical locks have never had to face.
In this article we examine in depth the main criticalities found in smart lock systems for self check-in and see how it is possible to mitigate them through safer design solutions.
Hardware weaknesses
- Removable external components: keypads and reading modules often house relays and accessible wiring, allowing manipulation or short-circuiting of wires after removing the panel.
- Poor internal segregation: in many devices the unlocking mechanism resides in the external terminal, rather than in a protected module inside the door, making any external shielding effort vain.
Software gaps
- Predictable or reusable codes: static PINs or common algorithms on multiple locks allow generating valid codes for multiple devices.
- Absence of attempt limits: without blocks or timeouts, a brute force attack can test thousands of combinations until discovering the PIN.
- Default credentials: debug or administrative interfaces protected by preset passwords often remain unchanged, opening digital "backdoors".
Wireless vectors
- Communication interception: Bluetooth or Wi‑Fi not always encrypted expose opening commands and network credentials in clear.
- Relay attack: BLE signal relay techniques can make the lock believe that the authorized smartphone is nearby, even though it is far away.
Maintenance and life cycle
Many low‑cost products exhaust firmware updates after 1–2 years, leaving known vulnerabilities without patches. Excessive dependence on external cloud services can also make the system inoperative in case of shutdown or service interruption.
Geva Elettronica: integrated security
Geva Elettronica addresses the main criticalities with a secure and resilient architecture.
Lock control on RS485 bus
The external terminal (keypad or reader) communicates via RS485 with an internal control module, located behind the door or in a protected panel.
- No accessible relay outside
- Anti-tampering: cutting or disconnecting the bus does not open the lock and keeps the door locked
Timed and offline codes
- Single-use and limited: each code has exclusive validity for the stay interval and becomes useless at the end, eliminating reuse or prolonged brute forcing
- Offline verification: the lock recognizes codes without Internet connection, zeroing risks of interception or cloud downtime
RFID badges for subsequent access
After the initial opening via PIN, the guest is provided with an RFID card valid for the entire duration of the stay.
- PIN exposure window reduced to a few minutes
- Recurring access managed by badge, without requiring numerical codes
Cloud independence
Once codes are generated, the system works autonomously, guaranteeing operational continuity even in the absence of network or long-term cloud support.
Conclusion
While many smart locks give in to physical tampering, software flaws and wireless attacks, the Geva Elettronica system stands out for a design that puts security first. The use of a protected RS485 bus, secure generation of temporary codes, offline support and use of RFID badges ensure a comfortable self check‑in experience but intruder-proof.