Asymmetric Key Design for Reversible Locking Security

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Solution Overview

Problem

Reversible keys with identical coding on both sides are vulnerable to easy copying and do not allow for higher-level locking security, restricting groove execution on the key tip and limiting variations, which compromises blocking security.

Innovation Solution

Designing a key with different coding on each side, allowing it to lock multiple locking systems when rotated, and incorporating various coding features such as grooves, millings, and control points on multiple surfaces, enabling superior functionality without being a reversible key itself.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If identical coding is used on both sides of the key, then the key can be inserted in either direction, but the key becomes easy to copy

Engineering Contradiction:
Improvereversible key functionVSAvoidcopying security
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent applies asymmetry by providing different coding on the first surface versus the second surface of the key. Specifically, the first coding includes a first curve while the second coding includes a second curve that differs from the first curve. This asymmetric design maintains the reversible key function (allowing insertion in either direction) while preventing easy copying, as unauthorized persons cannot simply replicate one side's coding to create a functional duplicate.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The patent introduces an additional dimension of complexity by adding surface-specific coding variations. Instead of uniform coding across both surfaces, the invention encodes different information on each surface (different curves, grooves, or other features). This dimensional expansion from identical to differentiated coding across surfaces significantly increases copying difficulty while preserving bidirectional functionality.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Device complexity

If identical coding is used on both sides of the key, then the lock design is simplified, but the number of key variations is limited

Engineering Contradiction:
Improvelock scanning elementsVSAvoidkey variations
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

By implementing different coding on each surface of the key, the patent dramatically expands the number of possible key variations. Each surface can have independent coding patterns (curves, grooves, positions), creating a combinatorial increase in unique key configurations. This asymmetric approach maintains relatively simple lock design while enabling vastly greater key diversity for master key systems and authorized personnel access.

Inventive Principle:
Principle #4Asymmetry

3Ease of operation

If lateral groove coding is used with identical curves on both sides, then the key can be reversible, but the middle locking pin at the key tip cannot be used

Engineering Contradiction:
Improvereversible key functionVSAvoidblocking security
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent resolves this contradiction by allowing asymmetric coding where the first curve on the first surface differs from the second curve on the second surface. This asymmetry enables the middle locking pin at the key tip to be engaged and controlled, as the different curves on each surface provide the necessary variation to control the locking mechanism's middle position. The key maintains reversible functionality while enabling full utilization of all locking pins for enhanced blocking security.

Inventive Principle:
Principle #4Asymmetry

Data Source

PatentEP3191663B1Key
Publication Date: 2021.06.09 EVVA SICHERHEITSTECHNOLOGIE GMBH
  • EP3191663B1 patent drawingFigure 1a~1d
  • EP3191663B1 patent drawingFigure 2a~2c
  • EP3191663B1 patent drawingFigure 3a~3b

AI summary

The invention relates to a key (1) for locking a lock, comprising at least one first surface (2) and at least one second surface (2'), having at least one scanning position (4) provided along the longitudinal extension of the key (1), on which at least one first coding (3) is provided on the first surface (2) for prompting in the lock and/or at least one second coding (3') is provided on the second surface (2') for prompting in the lock, wherein the at least one coding (3) of the first surface (2) at at least one scanning position (4) differs from the second coding (3') at the same scanning position (4). The invention further relates to a lock for such a key, and a system of at least two locks or lock groups and at least one key according to the invention.