In the old days, when signatures were used to sign cheques, there were people specialized in how to determine whether a signature came from a particular person or from a different person (forger).

Nowadays, signatures are often made out with an inkless pen (stylus) on a digital tablet.

I would like to know what techniques used to be used to check ink pen signatures on cheques in the old days, and what techniques can be used in modern times to check the validity of signatures signed with a stylus (where such precision in making this information out is, indeed, required). Where would you need such strictness?

I think this site (user experience SE) is the best stack exchange site for this question. I was not able to find a better site. Alternatively, this post could be migrated to the personal finance and money SE. But I don't think there's a close fit.

Thank you for your replies.



2 Answers 2


In the past, handwritten signatures were used to sign checks, and people specialized in determining whether a signature came from a particular person or a forger. Nowadays, signatures are often made with an inkless pen on a digital tablet, and new techniques are used to check their validity.

There are several ways to verify a signature:

Signature Analysis Handwriting analysis compared the signature with known samples. Experts looked for similarities and differences, examined pressure and direction of strokes, and used specialized equipment.

Real Signatures Experts look for unique characteristics such as size, shape, and slant of letters, style, flow, and the use of connecting strokes.

Fake Signatures Fake signatures are often less fluid and lack nuances and details of a real signature. Forgers may try to copy a signature, resulting in a similar but not identical signature.

Digital Signature Verification Digital signatures use encryption algorithms and require verification. Recipients use digital signature verification tools to ensure the signature is valid and created using a secure key or token.

Importance of Signature Verification Strict signature verification is required in financial and legal transactions to prevent fraud and ensure authenticity. Signature analysis is crucial to maintaining the integrity and authenticity of important documents and transactions.


There are definitely some fundamental differences between a digital and physical signature, because you can always easily clear a digital signature done with a stylus and re-sign it. The interaction of the stylus with the screen surface compared to that of pen and paper is also very different, but if it is the same person signing then you would expect a very consistent pattern when you compare all the signatures using a pen to that of a stylus.

Any form of handwriting analysis (regardless of the writing instrument and surface) requires some training data against the sample data in question, so I can't think how you would simply be able to verify the authenticity of a signature written using a stylus by comparing it to something done in pen and paper (and knowing what the difference is for that person as opposed to a forger), or without other signatures from the same person done in stylus as reference.

But in terms of the techniques of handwriting analysis, there are plenty of references that talk about the things to look for when making the determination such as:

  • Letter formations – how is the letter constructed, how many strokes, one continusous stroke of many strokes combined to make the letter.
  • Line quality – the dynamic process which guides the writing instrument across the paper and encompasses many elements such as pen pressure, speed, pen lifts, consistency of the written line, rhythm,
    and writing skill.
  • Alignment – alignment refers to the real or imaginary baseline upon which the writer places the writing.
  • Arrangement of the writing – With extended writing, the arrangement of the writing including margins, spacing, address placement,
    crowding or insertions may be as individual as the writing itself.

A signature is only a very short string of letters, which presents some complexity in the certainty or probability of the analysis compared to longer pieces of texts.

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