Sign PDF: How to Digitally Sign a PDF

Formal documents must be signed, regardless of whether they are on tangible paper or in digital format. Digital documents in formats such as PDF are phasing out paper documents. The resulting changes are mostly positive and beneficial. However, many first-time users don't know how to sign these digital documents.

Signing a PDF document digitally or electronically is easy, and you have several options with which to work. Here is a brief guide on how to digitally sign a PDF.

How to sign a PDF document

You need a program such as WinZip or Adobe to sign PDF documents digitally. The process varies depending on the platform you use, but understanding how digital signatures work will make it easy to sign any digital document in any format and on any platform.

How do digital signatures work?

Digital signatures are incorruptible codes (algorithms) that are based on asymmetric cryptography. The codes are like a digital fingerprint that serves as a sign.

The algorithm generates two keys: a private key that you use to sign the PDF document, and a public key that other people use to decrypt the code and open the document. The public key will not decode the private one if the document is corrupted, making the digital signature secure and reliable.

It is also important to differentiate between a digital and electronic signature. An electronic signature is an image of your hand-written signature overlaid on the PDF document. It doesn't require cryptography and algorithms. However, it is still legally enforceable.

How to sign a PDF document

The digital signature process varies depending on the program. However, the process is usually easy and only requires the click of a button. All you need is a digital certificate from your chosen program – the certificate is necessary to initiate the digital signature process.

The process is intuitive and doesn't take more than a couple of clicks, and your program will guide you as needed. Ensure that you follow the process to the letter.

Choosing the ideal digital signature program

It is important to pick the best program available to ensure that your digital signatures are secure and reliable. Some of the most important factors to consider include:

Security & reliability

One of the best aspects of digital signatures is their incorruptibility. However, this depends on the program's level of security and reliability. Some programs can be hacked, compromising your PDF documents' security and authenticity. As such, choose a program that guarantees security and reliability.


Most people often need more than just a digital signature solution. For example, you may need a solution to convert your document from a Microsoft Word version to a PDF version.

As such, it is advisable to find one that meets all of your needs. Fortunately, many digital signature programs come with these and more features. It is also advisable to get a digital signature solution that can support multiple signatures from multiple parties without compromising the document's credibility.


A signature is often the only way to verify a document's credibility. Some digital documents have proven unreliable during legal verification of the signatures. Consequently, it is advisable to find a solution that generates signatures that can be authenticated in court and enforced by all involved parties.

WinZip is one of the most versatile digital signature solutions. Its features include the ability to compress many documents into one small package to save time and space during transfer.


Digital signature solutions allow you to sign electronic documents at any time and from anywhere, easing your work. Solutions such as WinZip also enable you to do more with your documents, including converting them to other electronic versions, compressing many documents into one package, and storing them in a secure vault.

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