Pad Signature Verification Following the Tracks of Life Identity Declarations
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Automatic Signature Verification for Digital Ink Signatures

Signatures captured on Pen Pads, Signature Tablets and Tablet PCs

A dynamic signature captured and embedded in SOFTPRO E-Signing Solutions looks identical in all respects to a person’s original wet ink signature.

Some highlighted static and dynamic characteristics of a signature zoom Some highlighted static and dynamic characteristics of a signature

zoom image: Some highlighted static and dynamic characteristics of a signature

Some highlighted static and dynamic characteristics of a signature

It is much more than an electronic image only: Biometric information of handwritten signatures captured on appropriate devices contains data about the signature creation. Among the signals captured are location (x,y coordinates), time (t) and pressure levels of pen strokes (z). These partially invisible signals represent a biometric profile which is unique to every individual and can not be reproduced by a forger.
Best Practice Aspects for Capturing reliable Dynamic Signatures Data

A proper comparison of static signature characteristics and dynamic signature signals requires a digitizing instrument that is taking a sufficient amount of time signals. It also has to be able to differentiate between various pressure levels and to provide an appropriate resolution rate. These requirements are also reflected in the standard for the interchange of biometric signature data (ISO/IEC FDIS 19794-7). This standard was co-defined by SOFTPRO's scientists who play an active role now for years in the International Standardization Organization (ISO). SOFTPRO also collaborates with Forensic Institutes to secure best practice in Signature Verification.

  • Forensic experts require precise information on the relation of force applied and pressure levels. Manufactures of signature capturing devices must make available this sort of “pressure curve chart” to vendors of signature verification software and to the forensic experts.
  • A reliable capturing device has to record the same pressure levels in all segments of the capturing area with the same precision when the same force is being applied. When capturing signatures on different tablets of the same type from the same manufacturer signal data must not exceed a certain tolerance level, otherwise an analysis or verification would have to be adjusted to each device.
  • The ergonomics of the writing tablet must reflect the typical signing situation and ideally provide for a "paper-like" surface (which imitates the writing feeling on paper as close as possible).
  • The capturing technology must exclude the capturing of unwanted "overspill" information such as signals from a thumb ball that touched the capturing surface while signing.
  • In addition, for non-repudiation, security and auditing purposes, the capturing device must provide a unique serial number, a device id number* and trustworthy of the communication between device (firmware) and device driver (operating system).
Suitable Signature Capturing Devices