What people mean when they want to create a digital signature
When you set out to create digital signature files for contracts, forms or approvals, the first step is knowing which kind of signature you actually need. The phrase is used for three very different things, and they carry very different levels of evidence.
- An image of your signature. You draw your name in an online signature maker or scan a signature on paper, then paste the picture into a document. It looks like a signature, but it is only a picture. Anyone who has the file can reuse it, and nothing in it shows who placed it or whether the document changed afterwards.
- A certificate-based digital signature. In the technical sense, a digital signature is cryptography. Software uses a private key that only you control to sign the document, and a digital certificate links the matching public key to your identity. There may be no visible handwriting at all.
- A pen-captured handwritten signature. You sign with a pen on a signature pad or pen display. Software records the visible signature together with the pen data behind it, and can tie the signature to the exact document that was signed.
The free generators that dominate search results only make the first kind. For customer contracts, account forms and declarations, businesses normally need the second, the third, or both together.
How a certificate-based digital signature works
A certificate-based digital signature relies on a pair of keys: a private key kept by the signer and a public key that anyone can use to check the signature.
- The signing software calculates a hash of the document, a short fingerprint that changes completely if even one character of the file changes.
- The hash is encrypted with the signer’s private key. The result is the digital signature, which is stored in the file together with the signer’s certificate.
- When someone opens the file, their software uses the public key in the certificate to check the signature and recalculates the hash. If the two match, the document hasn’t changed since signing.
The certificate is what tells the recipient who signed. If it was issued by a trusted certification authority after checking the signer’s identity, the recipient’s software can confirm that identity. If it is self-signed, the maths still proves the file hasn’t changed, but the recipient has no independent proof of who created the certificate.
How to create a certificate-based digital signature
There are three common routes.
1. A certificate from a trust service provider
For signatures that third parties must be able to trust, you get a certificate from a certification authority or trust service provider. In the UAE, trust services are licensed by the Telecommunications and Digital Government Regulatory Authority (TDRA) under Federal Decree-Law No. 46 of 2021, and a qualified certificate can only come from a provider with qualified status.
2. UAE PASS for individuals
UAE PASS, the national digital identity, includes a Sign Document feature. TDRA describes how users upload a document in the app, sign it and download the signed PDF. UAE PASS documentation states that a fully verified account signs at qualified level, while some other verified accounts sign at advanced level. Government entities and private organisations can also integrate UAE PASS digital signing into their own portals.
3. A self-signed certificate
Office and PDF software can create a certificate for you on the spot. It is quick and useful for internal files, but because nobody has verified the identity behind it, it is the weakest of the three for documents sent to customers or partners.
How to create a handwritten digital signature with a Wacom pen
Many UAE businesses still need a real handwritten signature, especially when the customer is standing at a counter. A pen-captured signature keeps that familiar act and adds evidence that a picture can’t carry.
What gets recorded
According to Wacom’s developer documentation for its signature SDK, a captured signature is stored in a signature object that holds the signer’s name, the reason for signing, a date and time stamp, system information and the pen data. Wacom describes an eSignature as a high-speed recording of a handwritten signature that creates behavioural biometric data which can be uniquely linked to the signatory. The data is stored in Wacom’s Forensic Signature Store (FSS) format or in the ISO/IEC 19794-7 format, and both can be encrypted.
How it is tied to the document
Before capture, the application can calculate a hash of the document and store it inside the signature data. Later the hash is recalculated and compared, so any change to the document after signing can be detected. Wacom deliberately provides no API to extract the raw pen data, because it is personal information. When a signature is disputed, a qualified forensic document examiner can analyse it with Wacom’s SignatureScope application. We explain that comparison in the benefits of biometric signature verification.
What you need
- A pen device. A signature pad such as the Wacom STU-430 or the colour Wacom STU-540 captures the signature while the document stays on the staff monitor. A signature display such as the Wacom DTU-1141B lets the customer read the whole document and sign on the same screen. Our signature pad vs signature display guide compares the two.
- Signing software. Wacom sign pro PDF lets staff open, fill and sign PDF files without any development work. Our Wacom signature software overview covers sign pro PDF and the SDKs.
- Integration, if signing happens inside your own system. Developers can add capture to their own application with the Wacom Ink SDK for signature.
For the step-by-step setup, see our guide on how to sign PDF documents with a handwritten signature.
Combining a pen signature with a certificate
The two approaches are not either-or. In sign pro PDF, a digital certificate is part of the signing process: you can load one from a file or the Windows certificate store, or let the software create a self-signed one. Wacom recommends a certificate from a certification authority when signed documents go to many recipients, because a self-signed certificate does not let them verify who signed.
The result is a document that carries both the customer’s handwritten signature with its pen data and a cryptographic seal that shows whether the file has changed. That combination suits paperwork such as account opening and KYC forms, tenancy and rental agreements, insurance proposals and patient consent forms, where the business wants a familiar signing experience and a tamper-evident record.
Which method should you use?
- Internal approvals and low-risk paperwork: an image signature or a self-signed certificate may be enough, if your internal policy allows it.
- Remote contracts with partners or suppliers: a certificate-based digital signature from a trusted provider, so the recipient can verify who signed without meeting you.
- Customers signing in person: a pen-captured signature on a Wacom pad or display, sealed into the PDF. Banks and exchange houses also use it to capture reference signatures, as we explain in specimen signature meaning.
- Transactions that legally require a qualified signature: a qualified certificate from a TDRA-licensed qualified trust service provider, alongside any pen workflow you use.
For full contracts read and signed at a counter, see how to sign contract documents in person. For the banking side, read about electronic signatures in UAE banking.
Is a digital signature legally valid in the UAE?
It depends on the type of signature and the document. Under Federal Decree-Law No. 46 of 2021 on Electronic Transactions and Trust Services, an electronic document or signature cannot be refused as evidence just because it is electronic. The law also defines advanced electronic signatures, which must be uniquely linked to and controlled by the signatory and linked to the signed data so that later changes can be detected, and qualified electronic signatures, which need a qualified certificate and a qualified signature creation device. A qualified signature has the same legal effect as a handwritten one. Some document types can be excluded from electronic signing altogether.
A pen-captured signature sealed into a PDF gives strong evidence of who signed and that the file hasn’t changed since. The device alone does not make a document legally valid, and it does not turn a signature into a qualified one. Confirm the requirement for each document type with your legal or compliance team.
eTOP Trading is an Authorized Wacom Solution Provider and system integrator in the UAE. We help teams choose the right pad or pen display, set up signing software and connect signing to their existing systems.
Frequently Asked Questions
Can I create a digital signature for free?
Yes, you can make a signature image with a free online tool or create a self-signed certificate in office and PDF software. Neither proves your identity to the recipient. For documents that others must trust, use a certificate from a trust service provider or a pen-captured signature workflow.
Is a scanned signature the same as a digital signature?
No. A scanned signature is just a picture that can be copied into any file. A certificate-based digital signature is cryptographically tied to the document, and a pen-captured signature records pen data and can be bound to the document with a hash.
Do I need a certificate to sign with a Wacom signature pad?
Wacom sign pro PDF uses a certificate in the signing process and can create a self-signed one for you. Wacom recommends a certificate from a certification authority if you send signed documents to many recipients.
Can I sign documents with UAE PASS?
UAE PASS has a Sign Document feature that lets users sign a document in the app and download it as a signed PDF. The signature level depends on the account's verification status, and organisations can integrate UAE PASS signing into their own portals.
Does a signature pad make my documents legally valid?
Not on its own. A Wacom pad captures strong evidence of who signed and whether the document changed, but legal validity depends on the type of signature the transaction needs and on UAE law. Check each document type with your legal or compliance team.