How to sign documents electronically and can it be done?

In this age of computer technologies, the so-called electronic digital signature or abbreviated EDS was used to certify documents. However, in this issue, many do not have a clear understanding of why this is needed, since most people are used to working in the old fashion, signing documents manually. About how to sign documents by electronic signature, then we'll talk.

What is an electronic digital signature or EDS?

EDS represents a certain object in electronic form, according to which immediately it is possible to determine the person who formed it, to establish authorship, to verify the authenticity of the document, and so on.

Naturally, the EDS can visually look like an ordinary signature in the form of a graphic object inserted in the document. In fact, asymmetric encryption and cryptography algorithms work here. The EDS itself uses a private key and a key certificate, which makes it possible to determine the authorized person and the identity of the signature to him, the integrity of the document and confirmation of the fact of signing it.

Why you should sign EDS documents

Many people are somewhat puzzled over whether it is necessary and possible to sign documents electronically. This question can only be answered affirmatively. For a simplified understanding, consider one example.

Suppose a company represented by a general director should formalize a bilateral contract. It is clear that it will have to be visualized in any case, since without it it will not have legal force. But sending a ready contract, say, by fax is impossible. When sending by e-mail the graphic format of the scanned document is not welcome, because the signature can be faked. Thus, you have to send the same Word file, but this document must be signed. But how to sign the document "Vord" electronic signature? In general, this is nothing particularly difficult. Next, we will consider several simple methods for creating EDSs. In the meantime, let us dwell on legal issues.

Do I need to sign documents electronically manually?

Many office workers and managers believe that it is necessary to additionally (manually) need to (in any case, just in case) to visualize documents in which there is an EDS. The obvious fallacy. This is absolutely not necessary.

The matter is that when creating a digital signature and a certificate, a special agreement is made with the certifying center and certified by a notary, and at the stage of forming the certificate a private key is issued. From a legal point of view, this is the confirmation of the owner of the EDS. Thus, the conclusion suggests itself: a secondary sight is not necessary.

Algorithm of work with EDS

Let's find out how to sign the document with an electronic digital signature, and look at how it all works.

The basis of such processes is the creation of a cryptogram that hashes the verified file, defining owner data, authorship and data integrity. The created hash is encrypted with the private key at the next stage, after which either a whole document with the EDS is generated or a separate signature file linked to the document.

The recipient uses the public key to decrypt, authenticate (authenticate), and verify the integrity of the document. Of course, in general, most algorithms are very similar to each other. The difference can only appear depending on the type of software used.

How to sign a Word document with an electronic signature using the editor?

Many users do not even realize that EDS can be created quite simply even in the office Word editor. How to sign a "vordian" document with an electronic signature? As easy as pie. Actions in different versions of the editor are somewhat different, but in general they are the same. Consider creating a signature using the Word 2007 example.

So, how to sign documents electronically, using only Word? To do this, after inserting the cursor in the place where it is supposed to be signed, the insert menu is used, in which the text item is selected. Then you should find the item of the signature line and in the drop-down list set the MS Office signature line.

In the dialog box, you need to specify the data of the person signing the document, then select the scan of the original signature, then enter your own name in the box next to the "x" icon. After that, the printed version of the signature will be displayed.

On a tablet with a handwritten input, the signature can be put on its own. If you want to sign a document on behalf of more than one person, you will need to set up signature fields for each person.

You can do it simply by selecting the line "Prepare" in the menu of the "Office" button, then you specify the addition of the signature, then use the purpose of signing the document, then make the choice of the signature, and finally, the "Sign" item. The signing will be confirmed by the appeared red icon on the panel and the inscription stating that the document contains EDS.

The most popular tools for creating digital signatures

Now let's see what the solution to the problem of how to sign a document with a qualified electronic signature can be . To do this, it is desirable to use third-party software.

From the Russian-language software the most popular and most common are the following software packages:

• "CryptoARM";
• "Crypto PRO";
• CryptoTri.

The first program looks the most simple, therefore further it will be considered how to sign documents by electronic signature, it is with its help.

Creation of digital signature on the example of the application "CryptoARM"

To create a digital signature with this application, there are two methods: using the context menu and performing actions through the main interface of the program. For a simpler understanding of the process, let's dwell on the first option, especially since the second one is almost identical, only the main action is called directly from the program. Suppose you need to digitally sign a Word document.

First, in the "Explorer" you need to select the document we are interested in and select the line "Sign" in the menu of the RMB. After that, the "Masters" window will appear, which will help to perform all further actions. We press the continuation button and check if the file is selected. If necessary, you can add more objects to make them simultaneously sign.

Press the "Next" button again and select the encoding method in the next window. In principle, you can not change anything and leave the default settings. In the next step, you can enter additional data (time stamp, visa, etc.). Along the way, you can select the checkbox in the field to save the signature as a separate object (when you check the signature in the document, both files will be required). If you do not put a tick, the signature file will be merged with the document.

After the continuation, you will need to select a certificate that was issued by the appropriate certification authority (it can be on an external eToken media or registered in the system registry). After that, the remaining parameters can not be changed. At the end of all actions, you will only have to click the "Finish" button.

Note: if a separate file was selected for the signature, as a rule, it will be located in the same directory as the original document to be signed, and have a SIG extension.

Features of signing documents PDF, HTML and XML

Finally, a few words about other formats. In principle, for PDF documents, the actions will be the same, but due to the specifics of other programs from Adobe, it is advisable to separate the signature file from the main document.

It is possible that the recipient of the document will first want to get acquainted with its contents using the same Acrobat (Reader), and only then will it check the signature. By the way, some applications from Adobe also allow you to sign files with your own regular means.

If you embed the signature in HTML documents when working with thin clients, the browser will need to click on "Sign and send", after which the developer script will be activated, which forms a string variable with data on the document verification that will be entered in a special hidden field, signed and Transferred to the server by the POST method. Then the document and the signature will be checked, after which a table with the fields of the signed document and its EDS will be created on the server.

You can sign XML files as regular documents, use the InfoPath Office tool, or create a special tag attribute in the document itself.

Summary results

Here is a short and all about how to sign documents electronically. Of course, not all methods that allow such operations to be performed have been listed here, and not all programs for creating digital signatures have been considered. However, even with such a brief description, one can already understand what an electronic signature is for, and how all the necessary algorithms work.

If you look at some types of software, in particular, office programs or the most popular products from Adobe, you can use their own tools. However, in terms of simplifying the work, at least to a novice user, it is better to use third-party utilities as an example with CryptoARM. It goes without saying that one should not forget about the legal side of the matter. Some companies create electronic signatures and certificates on their own, but in the end they are not that they are not valid, but they do not have legal force.