La verification of electronic documents It has become commonplace when dealing with public administration, online procedures, or official notifications. It's increasingly common to receive a resolution, a receipt, or a communication in PDF format instead of the traditional paper letter, and it's natural to wonder if the file is authentic, if it can be printed without losing its validity, or how to verify that it hasn't been tampered with.
To address all of this, the Administration has developed specific systems, among which the following stands out: Secure Verification Code (CSV)This tool allows you to verify the document's integrity and download the original, electronically signed version. Throughout this guide, we'll explain in detail, using the clearest language possible, how this verification works, what guarantees it offers, and what you need to use it without complications.
What is electronic document verification?
When we talk about verification of electronic documents We are referring to the process that allows us to confirm two essential things: firstly, that the document is authentic (that is, that it was actually issued by the body or administration that claims to have generated it) and, secondly, that its content has not been modified since it was electronically signed. This verification is carried out through the electronic headquarters of the issuing body.
In practice, the system allows anyone to retrieve the electronic document with your original signature Using a unique identifier printed on the paper copy or PDF: the well-known Secure Verification Code. Simply enter this code on the corresponding website to compare what you have with what is stored on the official website.
This procedure is supported by the Law 40/2015, on the Legal Regime of the Public SectorArticle 42.b of this law allows for the use of verification systems through codes associated with electronic documents. This ensures a clear legal framework that gives full validity to printed copies as long as the link to the original electronic document is maintained.
Many government agencies, such as the Directorate General of Traffic (DGT) or various ministries, offer a specific service on their websites for View and download electronically signed documentsThrough these services, you can access the original file in formats such as XAdES, CAdES, or PDF, as well as verify the associated signature and timestamp.
In addition to the verification itself, these services allow citizens to keep a digital copy with all guarantees of authenticity and integrityThis is especially useful in dealings with other administrations, in legal proceedings, competitive examinations, appeals, or any situation in which it is necessary to provide documents with official validity.
What is a Secure Verification Code (CSV)?
El Secure Verification Code (CSV) It is the central element of the electronic document verification system in the Public Administration. It is a string of digits (sometimes combined with letters) that uniquely identifies each electronic document issued by a ministry, public body, or public law entity.
This code is linked to the document and the issuing bodyTherefore, when it is entered into the corresponding electronic portal, the system locates the original document stored on the Administration's servers. This allows verification that the content of the copy we have in hand exactly matches the official file.
In most cases, the CSV is printed on every single page of the document, usually in a visible area of ​​the margin, header, or footer. This ensures that even if only part of it is photocopied or printed, there is always a direct link to the electronic original.
Thanks to this system, any paper copy of an official electronic document that include the CSV It can be considered an authentic copy, provided it can be verified through the corresponding electronic portal. It is precisely at this point that online verification becomes crucial, as it is the tool that provides legal certainty to copies.
When a document incorporates CSV files, the user can use it to verify the authenticity of the content at any time. If the code is entered on the official website and the system returns the same document, with the same text and data, the copy is considered reliable. If, on the other hand, the code does not exist or the document does not match, manipulation or fraudulent use is suspected.
What documents can be verified with CSV
In general, you can verify all issued electronic documents by a public body that include a visible CSV code. Each administration manages its own document repository and has an electronic headquarters or query service associated with these codes.
The Directorate General of Traffic, for example, allows you to verify the integrity and authenticity of any document it has issued that bears a secure verification code associated with the DGTThis may include resolutions, notifications, permits, sanctions, reports or proof of procedures, provided they are identified with a CSV issued by said body.
If the CSV document belongs to another different organismThe verification cannot be done at the DGT headquarters; it must be done on the issuer's website. In other words, if the document was issued by a specific ministry, autonomous community, or city council, you will need to go to that organization's official website to enter the code.
The verification tool usually also allows the Download the electronically signed document in various formats. It's common to find files in XAdES or CAdES (advanced signature formats) and in PDF, along with the original document to which the electronic signature was applied. This simplifies archiving and subsequent presentation, as it can be saved on a computer or mobile device with complete security.
It's important to understand that if no record appears when you enter the CSV file, it could be a... document that has not been registered by the agency consulted or an error in the code. In the case of the DGT, for example, if the document cannot be found, it is recommended to go to a Traffic Headquarters or Office to verify the situation following the procedure that the organization itself has established.
How the CSV verification system works
The system's practical operation is quite simple for the user, despite the complex technical infrastructure behind it. In broad terms, it simply requires that Enter the CSV file of the document you wish to view. in the form enabled on the electronic headquarters of the corresponding administration.
The verification screen usually displays a specific field for the Safe Code of VerificationThis is usually mandatory. The user enters the code exactly as it appears in the document margin (respecting numbers and, where applicable, letters and separators) and submits the query. If the code is valid, the system returns the original document or the information associated with it.
On many portals, after entering the CSV and clicking on "consult", you receive a confirmation of the integrity and authenticity of the documentThis is accompanied by the option to download the electronically signed file. This allows you to visually verify that what you have matches what the Administration keeps in its official repository.
Some services add additional security measures, such as identification using electronic ID card or digital certificate in special cases. This occurs especially when the nature of the procedure or the sensitivity of the data requires ensuring that the person consulting is the person authorized to do so, or an authorized representative.
Once downloaded, the document can be stored on your computer, tablet, or mobile device, maintaining the legal validity of the electronic signature and the timestamp, provided the content is not altered. This allows it to be reused in other procedures and presented to third parties, who can then verify the CSV on the corresponding electronic portal.
Requirements for verifying an electronic document
To verify an electronic document through its CSV, a large technical infrastructure is not required, but certain requirements must be met. basic internet access requirementsThe only essential requirement is to have the code that appears in the document and an internet connection to access the organization's website.
In most cases, one is sufficient updated web browser and a device to access the official website (computer, laptop, tablet, or smartphone). Verification portals are usually optimized to work correctly on mobile devices and tablets, so it's possible to complete the process on the go without needing to be in front of a desktop computer.
In certain situations, the Administration may require a enhanced electronic identificationThis is especially important if sensitive information is being accessed or if further actions are to be taken based on the consulted document. In these cases, the user may be asked to use their electronic ID card, an accepted digital certificate, or the identification system used by the electronic office (for example, Cl@ve).
However, basic verification of a document's authenticity using CSV files is usually available without installing anything special beyond the usual browser components. The important thing is to always go to the... official website of the issuing body to avoid fake pages or scams that try to impersonate the Administration.
It's also a good idea to make sure the URL starts with https and displays a valid certificate, as this confirms that the connection is secure and that the data entered (such as the CSV or, where applicable, the ID card) travels encrypted and protected from third parties.
Download, copies and validity of verified documents
Once an electronic document has been verified using CSV, the platform will usually allow download the electronically signed document and, in many cases, the original document on which the signature was applied. This is offered in standard formats, such as PDF, or in advanced electronic signature formats such as XAdES or CAdES.
These downloads are especially useful because they allow you to keep digital copies that maintain all guarantees of authenticity and integrityThe user can save them on their computer or mobile device, integrate them into their document management system, and submit them in other procedures without having to constantly request new copies from the Administration.
Furthermore, any paper copy generated from the original electronic document, provided it includes the Secure Verification Code clearly visibleIt can be considered an authentic copy. The key is that any third party who receives that copy can later go to the electronic headquarters to compare its content with the official document.
This represents a great advantage over the traditional system in which it was necessary certify documents or physically go to the offices to obtain stamped copies. Now, the CSV itself and the possibility of online verification fulfill that guarantee role, reducing time, travel and costs for citizens and businesses.
If the document cannot be found when entering the CSV file on the electronic portal, or if any discrepancy is detected between the copy you have and the file that appears in the system, the recommended course of action is contact the issuing body directlyIn the case of the DGT, for example, you can go to a Traffic Headquarters or Office to have the file reviewed and the incident clarified following the established internal procedure.
Authenticity, integrity and immutability: how the electronic signature guarantees it
Behind the verification system and the use of the CSV there is a key piece: the Advanced electronic signature with timestampThis technology is what makes electronic documents issued by the Administration unalterable for legal purposes and allows any subsequent modification to be detected immediately.
When an organization electronically signs a document, two basic technical operations are performed. First, a fixed-length digital hash or summary based on the entire content of the document. This summary is a unique fingerprint: any change, however small, will generate a completely different result.
Then, that summary cipher with the private key associated with the issuer's certificate (for example, from a ministry or directorate general). The encrypted digest is packaged along with the document, but the visible content of the file is not encrypted, so the citizen can read it without needing any special key.
To subsequently validate the electronically signed document, the system performs three steps: it recalculates the hash from the current content The document is decrypted using the public key contained in the issuer's certificate, and the two fingerprints are compared. If the two fingerprints match, the document is considered unmodified since it was signed, and therefore the signature is valid.
If, on the other hand, the summaries are not identical, it is concluded that there has been a alteration in content Consequently, the signature is considered invalid. This way, any attempt at manipulation is immediately detected, offering a high degree of security for both the administration and the citizens who receive the document.
Properties of the digital hash and system security
The method for calculating the digital summary (hash) used in the electronic signature presents three fundamental characteristics which explain why it is so secure for protecting administrative and notarial documents.
On one hand, the hash always has a fixed length, regardless of size of the document. It doesn't matter if the file is a single sheet or a dossier of hundreds of pages; the numerical or alphanumeric result of the summary always occupies the same space, which facilitates its use in cryptographic processes.
Secondly, a minimal modification to the content (for example, changing a single letter or number) produces a completely different summaryThis extreme sensitivity to any change makes it virtually impossible to alter a document without the system detecting it when recalculating the hash.
The third key property is that summary calculation is a process not symmetric: the hash can be easily obtained from the textHowever, it's not possible to reconstruct the original text from that summary alone. In other words, the hash doesn't reveal the document's content, but it does allow for its unique identification.
By combining these properties with the encryption of the digest using the sender's private key and its validation through the public key, a system is built robust and reliable electronic signatureThis is what allows the Administration to stop depending on paper as the only medium with legal value and move towards a fully digital management.
Common problems when verifying electronic documents
Although the CSV verification system is robust and widely used, some practical issues can arise when using it. One of the most frequent problems is unable to verify the document because the code is not recognized by the electronic platform where it is being entered.
In many cases, this is simply because the The document has not been issued by the agency. whose headquarters we are using. Since each administration manages its own codes, if you try to verify a CSV code belonging to a different ministry or autonomous community with the DGT (Spanish Directorate General of Traffic), the system will not find anything.
Another fairly common mistake is having The code was copied incorrectly.This can happen either by confusing numbers and letters (for example, a zero with an O) or by omitting a character. It's advisable to carefully review the CSV file and exactly respect the format that appears in the document, including separators if there are any.
It is also possible that the document has been issued correctly but is not yet available. registered or replicated in the query system at the time we tried to verify it. In this case, it is advisable to wait a reasonable amount of time and try again, or contact the issuing body to confirm the situation.
If the problem persists after several checks, the safest course of action is contact the responsible office or unit (for example, a Traffic Headquarters in the case of DGT documents) so that they can check the CSV internally and clarify whether the document is valid, whether there has been any administrative error or whether it is a possible fraud.
This entire framework of electronic signatures, timestamps, and Secure Verification Codes ensures that electronic documents issued by the Administration have full legal validity and that anyone can verify their authenticity from home. Understanding how this system works and knowing how to use it effectively allows you to take full advantage of online processing and maintain copies with legal guarantees comparable to paper and detect any manipulation immediately, which has become a key part of modern administrative management.
