In modern business, the need to sign a contract, act or certificate arises at the most unexpected moment, when there is no printer and scanner at hand. Fortunately, smartphones based on Android have sufficient computing power and functionality to replace an entire office. Electronic signature from the phone screen becomes a legitimate tool that allows you to complete transactions remotely without violating deadlines and legal norms.
Process applying a visualized signature or using a full qualified electronic signature (QES) on a mobile device has become much easier in recent years. Application developers have introduced intuitive interfaces, and manufacturers Android improved work with touch screens and styluses. In this article, we will examine in detail the methods of creating a signature, from simple finger drawing to the use of secure cryptographic keys.
Regardless of whether you just need to sign on a courier invoice or sign a legally binding agreement with a counterparty, your gadget will cope with this task. It is only important to choose the right tool for the specific type of document and the level of security required.
Preparing a document for signing
Before moving on to the creative process of drawing with a pen (or finger), you need to correctly import the file into the workspace of your device. Most often, documents come in PDFformat, which is the de facto standard for immutable files. However, sometimes you have to deal with scans in the format JPEG or PNGreceived via instant messengers.
If the file is located in a cloud storage, such as Google Drive or Yandex.Disk, it is better to first save it to the local memory of the phone. This will eliminate access problems in case of an unstable Internet connection during work. Open the file manager, find the downloaded document and make sure that it is not damaged and can be opened with standard viewing tools.
⚠️ Attention: Never edit the original file directly if it is the only copy. Always make a copy of the document before making any changes, including adding a signature, to keep the source intact for archiving.
Working with text files such as DOCXmay require conversion to PDF, as most signature tools are focused on this format. This ensures that the layout of the document will not “go wrong” when opened on the recipient’s device. Use the built-in functions of office packages or online converters for this procedure.
Using built-in PDF viewers
Many users do not realize that basic annotation tools are already built into the system or popular browsers. In the ecosystem Android application Google PDF Viewer (often part of Google Drive) allows you to add simple graphic elements on top of the document. This is an ideal option for everyday situations when complex cryptography is not required.
To use this method, open the document in the viewer and look for the pencil icon or the "Edit" button. From the menu that appears, select a drawing tool. You will be asked to select a color (usually black or blue) and line thickness. Carefully sign in the designated place using your finger or stylus.
The advantage of this method is its speed and the absence of the need to install third-party software. However, the functionality here is limited: you cannot save the signature as a template for reuse, and the quality of the line is highly dependent on the sensitivity of your smartphone screen. For important documents, this method may not look professional enough.
Use a stylus instead of your finger to create a clearer, neater signature. If you don't have a stylus, try using a cotton swab lightly moistened with water for better conductivity and accuracy.
After applying the stroke, be sure to click the "Save" button or the floppy disk icon. The system will generate a new file or update the current one, embedding your drawing in the annotation layer. Check the result by scrolling to the end of the page to make sure that the signature does not overlap important text and is positioned correctly.
Specialized applications for electronic signature
For regular work with documents, it is advisable to install specialized software that turns the phone into a full-fledged document management tool. The market leaders are applications like Adobe Fill & Sign, DocuSign or domestic analogues that support work with EDS. These apps allow you to create a digital image of your signature once and use it many times.
The setup process usually begins with creating a profile. You are asked to draw a signature on a white background, after which the app's algorithm cuts it out, removing the background and smoothing the edges. The resulting object is saved in the library and can be inserted into any document in one click. In addition, such applications often allow you to add a date and checkmarks to the required form fields.
- 📱 Automatic filling: the application remembers your data (full name, position) and inserts them into the appropriate fields.
- ☁️ Synchronization: signed documents are automatically sent to the cloud or to the counterparty’s email.
- 🔒 Security: the ability to block access to the application with a password or fingerprint.
Particular attention should be paid to applications certified to work with a strong qualified signature, for example, CryptoARM or solutions from Kontour. They require the installation of additional security modules and certificates, but provide the legal significance of the document equal to the original paper with a seal.
☑️ Setting up a signature application
Signing documents using a token and CEP
When it comes to submitting reports to the tax office, participating in tenders or signing bank guarantees, a simple picture with a stroke is not enough. Required qualified electronic signature (QES). On the platform Android this procedure is possible thanks to the support of technology NFC and special container applications.
To work, you will need a physical key carrier - a token (for example, Rutoken or Jacarta) with a recorded certificate, as well as a smartphone with a contactless communication module. Connection is carried out by applying the token to the back cover of the phone. The application reads the key, requests PIN code and allows you to sign the file with a cryptographic algorithm.
| Signature type | Legal force | Required equipment | Setting complexity |
|---|---|---|---|
| Simple (picture) | Low (additional agreement required) | Smartphone only | Minimal |
| Unqualified (NEP) | Average (for internal document flow) | Smartphone + certificate in the cloud | Average |
| Qualified (KEP) | Full (equal to handwritten) | Smartphone + NFC token + PIN | High |
It is important to consider the compatibility of your device with specific types of tokens. Not all smartphones work correctly with all reader models due to differences in the implementation of the stack. Before purchasing a token, check the list of supported devices on the website of the manufacturer of the cryptographic information protection tool. Android work correctly with all reader models due to differences in stack implementation NFC. Before purchasing a token, check the list of supported devices on the website of the manufacturer of the cryptographic information security tool.
⚠️ Attention: When working with CEP on a mobile device, it is critical not to transfer the PIN code from the token to third parties and not to store it in the phone notes. Losing control over the key can lead to fraudsters signing documents on your behalf.
The nuances of working with the touch screen and stylus
The quality of the visual part of the signature directly depends on the accuracy of the input. On screens without an oleophobic coating or when using thick protective glass, the finger may “float”, making the stroke unclear. In such situations, using an active stylus becomes not just a convenience, but a necessity for business etiquette.
Modern flagship smartphones, such as the Samsung Galaxy Note or S Ultraseries, are equipped with built-in pens that support thousands of pressure levels. This allows you to vary the thickness of the line depending on the pressure applied, simulating a real pen. If you have a regular device, you can purchase a universal capacitive stylus with a thin disk at the end.
What to do if the screen responds with a delay?
If you notice lags when drawing a signature, close background applications and clear the RAM. Also check to see if the power saving mode is turned on, which may limit the sensor polling rate.
When signing, keep the phone on a hard surface, not suspended. This will minimize hand shaking and allow you to draw the line with confidence. If a document requires signatures in several places, try to maintain the same style and size of strokes so that it looks natural.
Verifying the authenticity and sending the document
Once the document is signed, the final stage is checking the integrity of the file and sending it to the recipient. If you used a simple graphic signature, just save the file in PDF format and send it by email or messenger. The recipient will be able to open it on any device without losing formatting.
If a cryptographic signature is used, the verification process becomes more complicated. The recipient must be able to verify the certificate. Often, along with the signed file, a verification report or signature file with the extension .sigis automatically generated. Make sure that you are sending the entire package of files, and not just the document itself.
Some electronic document management services (VLSI, Diadoc) have their own mobile applications that take over the verification process. In this case, you just need to click the “Sign” button inside the application, and the system itself will generate a legally significant package, sending it to the counterparty via a secure communication channel.
Always save a copy of the signed document in a separate "Sent" or "Archive" folder in order to have proof of the fact of signing and the contents of the document on a specific date.
Frequently asked questions (FAQ)
Can I sign a document via phone without the Internet?
Yes, if you use a simple graphic signature or a pre-loaded EPC certificate, the Internet is not required for the signing process. It will only be needed at the stage of sending the finished file to the recipient or to check the status of the certificate in the registry.
Will a signature drawn with a finger have legal force?
The picture itself with a stroke is not valid unless an agreement has been concluded between the parties on the use of a simple electronic signature. For ordinary contracts between individuals or within a company with a signed agreement, this method is acceptable.
How to sign a document if I do not have a stylus and my finger slips?
Try to zoom in on the document to the maximum before drawing. This will allow you to make more precise movements on a small area of the screen, which, after zooming out, will look like a neat line.
Is it safe to store electronic signature certificates on a smartphone?
Storing certificates in cloud application storage or on encrypted tokens is considered safe, subject to the rules of digital hygiene. The main thing is to use a strong password to enter the device and not give access to the phone to strangers.