Online Signature Verification (Dynamic)
Analyzes pen dynamics such as pressure, speed, and trajectory to authenticate handwritten signatures.
Overview
Online signature verification captures the dynamic process of signing to provide stronger assurance than static image comparison.
How it works
- Capture pen movement and pressure over time.
- Extract features like speed, direction, and acceleration.
- Compare against stored signature templates using temporal alignment.
Common use cases
- Financial document signing
- Point-of-sale terminals
- Digital contracts requiring biometric evidence
Strengths and limitations
Strengths: Difficult to forge precisely; continuous temporal data.
Limitations: Requires specialized tablets or stylus input.
Key terms
- Dynamic features: Time-based measurements of the signing process.
- DTW (Dynamic Time Warping): Technique for aligning signature trajectories.
References
Frequently Asked Questions
What data is captured?
Time-stamped x/y coordinates, pressure, and sometimes pen-tilt or velocity.
How is it different from image-based signature matching?
Online methods use temporal dynamics captured during signing, which are harder to forge than a static image of a signature.
What sensors are used?
Signature tablets, stylus-enabled devices, or capacitive touchscreens with pen support capture the necessary dynamics.