In our age of computer technology, the so-called electronic digital signature or abbreviated EDS has become used for document certification. However, in this matter, many do not have a clear understanding of why this is necessary, because most are used to working the old fashioned way, signing documents manually. How to sign documents by electronic signature will be discussed further.
What is an electronic digital signature or digital signature?
EDS is a certain object in electronic form, by which you can immediately determine the person who formed it, establish authorship, verify the authenticity of the document, etc.
Naturally, visually EDS can look like a regular signature in the form of a graphic object inserted into a document. In fact, asymmetric encryption and cryptography algorithms work here. The EDS itself uses the private key and key certificate, which allows you to determine the trustee and the signature to him, the integrity of the document and confirmation of the fact of its signing.
Why should you sign EDS documents
Many are somewhat perplexed as to whether it is necessary and possible to sign documents with an electronic signature. This question can only be answered in the affirmative. For easier understanding, consider one example.
Suppose a company represented by a general manager must issue a bilateral contract. It is clear that it will have to be endorsed in any case, since without it it would not have legal force. But sending the finished contract, say, by fax is not possible. When sending by e-mail, the graphic format of the scanned document is not welcome, because the signature can be falsified. Thus, you have to send the same Word file, but such a document must be signed. But how to sign a Word document with an electronic signature? In general, this is not particularly complicated. Next, we will consider several simple methods for creating EDS. In the meantime, dwell on legal issues.
Do I need to sign documents with electronic signature manually?
Many office workers and managers believe that they need to endorse documents in which there is an electronic digital signature (manually) (so to speak, just in case). Clear error. This is completely optional.
The fact is that when creating a digital signature and certificate, a special contract is drawn up with a certifying center and is notarized, and at the stage of generating 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.
EDS algorithm
We will figure out how to sign a 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 authenticated file, determining the owner’s data, authorship and data integrity. At the next stage, the created hash is encrypted using the private key, after which either the whole document with the digital signature is formed, or a separate signature file is attached to the document.
The recipient uses the public key to decrypt, authenticate (authenticate) and verify the integrity of the document. Of course, in general terms, 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 by electronic signature using the editor?
Many users do not even realize that the digital signature can be created quite simply even in the office Word editor. How to sign a “Word” document with an electronic signature? Easy peasy. Actions in different versions of the editor are slightly different, but in general the essence is the same. Consider creating a signature using Word 2007 as an example.
So, how to sign documents electronically using only Word? To do this, after placing the cursor in the place where you intend to put the signature, the insert menu is used, in which the text item is selected. Then you should find the signature line item and set the MS Office signature line in the drop-down list .
In the settings dialog box, you must specify the data of the person signing the document, then select the scan of the original signature, and then enter your own name in the box next to the “x”. After that, a printed version of the signature will be displayed.
On a tablet with handwriting, you can put your signature on your own. If you want to sign a document on behalf of several persons, you will need to configure the signature fields for each person.
You can do it easier by selecting the line “Prepare” in the menu of the “Office” button, then specify adding a signature, then use the purpose of signing the document, then make a choice of signature, and finally, select “Sign”. The signature will be confirmed by the appearing red icon on the panel and the inscription stating that the document contains an electronic digital signature.
The most popular tools for creating EDS
Now let's see what a solution to the problem of how to sign a document with a qualified electronic signature can be . For this, it is advisable to use third-party software.
Of the Russian-language software, the most popular and most common are the following software packages:
- "CryptoARM";
- Crypto PRO;
- CryptoTree.
The first program looks the simplest, so it will be further discussed how to sign documents with an electronic signature, precisely with its help.
Creating an EDS using the CryptoARM application as an example
There are two methods for creating a digital signature using this application: using the context menu and performing actions through the main program interface. For a simpler understanding of the process, we dwell on the first option, especially since the second 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 of interest to us and in the RMB menu select the line "Sign". After that, the “Wizards” window will appear, which will help you perform all further actions. Click the continue button and check if the file is selected. If necessary, you can add a few more objects to implement their simultaneous signing.
Press the “Next” button again and in the next window select the encoding method. In principle, you can not change anything and leave the settings proposed by default. At the next stage, you can enter additional data (time stamp, visa, etc.). Along the way, you can select the checkbox in the field for saving the signature as a separate object (during the subsequent verification of the signature in the document, both files will be required). If you do not check, the signature file will be merged with the document.
After continuing, you will need to select a certificate that was issued by the appropriate certification authority (it can be located on an external eToken or registered in the system registry). After that, the remaining parameters can be left unchanged. At the end of all the steps, it remains only to click the “Finish” button.
Note: if a separate file is selected for signing, as a rule, it will be located in the same directory as the original document to be signed and have the SIG extension.
Signature Features of PDF, HTML, and XML Documents
Finally, a few words about other formats. In principle, for PDF documents, the actions will be the same, however, due to the specifics of other programs from Adobe, it is advisable to separate the signature file from the main document.
A situation is possible when the recipient of the document first wants to get acquainted with its contents, using the same Acrobat (Reader) for this, and only then it will verify the signature. By the way, some applications from Adobe also allow you to sign files using your own regular means.
If you embed a signature in HTML documents when working with thin clients, you will need to click "Sign and Send" in the browser, after which the developer script will be activated, generating a string variable with data for document verification, which will be entered in a special hidden field, signed and transferred to the server using the POST method. Then, verification of the document and signature will follow, after which a table will be formed on the server with the fields of the signed document itself and its digital signature.
XML files can be signed as regular documents, use the InfoPath Office tool or create a special tag attribute in the document itself.
Brief Summary
That’s briefly and all about how to sign documents electronically. Of course, far from all the methods that make it possible to carry out such operations were given here, and not all programs for creating digital signatures were considered. However, even by such a brief description it is already possible to understand why an electronic signature is needed, and how basically 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 for a novice user it is better to use third-party utilities as an example with "CryptoARM". It goes without saying that we should not forget about the legal side of the issue. Some companies create electronic signatures and certificates on their own, but in the end they are not that they are not valid, but they have no legal force.