What is an E-Signature? And How Does It Work? A Detailed Guide

What is an E-Signature?

As the digitalization process rapidly advances in Ankara, Turkey, the question “What is an E-Signature? And How Does It Work?” holds great importance for both individual users and corporate firms. Replacing traditional wet signatures, the electronic signature (e-signature) emerges as a technology that enables documents to have legal validity in a digital environment. But what exactly does this technology represent, how does it function, and why is it so crucial? In this article, we will thoroughly examine everything from the fundamental principles of e-signatures to their areas of use, from their legal validity to their technical infrastructure. Our aim is to explain this seemingly complex topic in a simple and clear language that anyone can understand.

What is an E-Signature? More Than Just a Definition

An electronic signature is a tool used to verify the identity of the signatory and ensure the integrity of data created in an electronic medium. However, the term “electronic signature” used in daily life is actually an umbrella concept that covers different types. In Turkey and the European Union, the most widely accepted type of e-signature is the qualified electronic signature (QES), which has a special security infrastructure.

A wet signature shows that a document has been approved by the signatory and is made with ink on the paper itself. An e-signature, on the other hand, is a digital dataset that is attached to a document digitally. This data is cryptographically linked to the content of the document. This means that even the slightest change made to the document’s content will cause the signature to lose its validity. This feature makes the e-signature far superior to a wet signature in terms of security and integrity.

Core Components of an E-Signature: Everything Is Not a Secret

To understand how an e-signature works, it is necessary to know its core components. These components are the building blocks that ensure the e-signature’s security and legal validity.

Certificate: The most critical component of an e-signature is an electronic certificate that digitally verifies the identity of the signatory. This certificate is issued by an authorized Electronic Certificate Service Provider (ECSP). These institutions are independent organizations that meticulously carry out identity verification and securely create the certificate. In Turkey, institutions providing this service include TÜBİTAK BİLGEM, E-Güven, and TürkTrust.
Smart Card or USB Token: A qualified electronic signature is typically stored in a special hardware device called a smart card or USB token. These devices securely protect the signature’s private key and ensure that the signing process is performed only by the authorized person. Physically protecting the private key in this way prevents malicious individuals from accessing the key and creating forged signatures.
Private Key and Public Key: These two keys, which form the basis of the world of cryptography, are at the heart of the e-signature. The private key is known only to the signatory and is used to sign documents. The public key, on the other hand, can be shared with anyone and is used to verify the authenticity of a signed document. The two keys are mathematically linked, and this connection guarantees that the signature cannot be replicated.

How Does an E-Signature Work? A Technical Journey

Signing a document with an e-signature involves a process that is much more complex than simply pressing a button. Here is the step-by-step e-signature process:

Creating a Document Hash: First, the entire document to be signed is converted into a mathematical hash using a hash algorithm. This hash is like a unique “fingerprint” of the document. No matter how long the content of the document is, the hash value always has a fixed length. This process is vital for protecting the integrity of the document.
Encrypting the Hash (Signing): The created hash value is encrypted using the signatory’s private key. This encrypted hash value is, in fact, the electronic signature of the document. The signature is created on a special chip inside the smart card or USB token, and the private key never leaves the device.
Attaching the Signature to the Document: The encrypted hash value (e-signature) and the signatory’s digital certificate are attached to the signed document. This trio (document, e-signature, and certificate) now becomes an integrated file. The file is now a legally valid and reliable document.
Verifying the Signature: The signature verification process works in reverse of the signing process. When a recipient receives an e-signed document, they first re-create their own hash of the document. Then, the signature within the document is decrypted using the signatory’s public key, and the original hash value is obtained. If the new hash value created by the recipient is identical to the decrypted hash value, it indicates that the document has not undergone any changes since it was signed. Additionally, the certificate information is checked to confirm that the signature was genuinely made by an authorized person and that the certificate’s validity period has not expired.

This two-stage verification process is the greatest guarantee of the e-signature. Both the integrity of the document and the identity of the signatory are verified simultaneously.

Areas of E-Signature Use: In Every Aspect of Our Lives

The e-signature is not just a technological innovation but a tool that fundamentally changes the way we do business. Its use is rapidly becoming widespread in both the public and private sectors.

E-Government Services: Many transactions conducted through the e-government portal in Turkey can be carried out with an e-signature. Many official documents, such as SGK transactions, tax declarations, commercial registry transactions, and passport applications, can be signed without physically going to institutions.
Legal Processes: The use of e-signed documents is increasing in courts and notaries’ offices. Legal documents such as contracts, powers of attorney, and notifications gain legal validity when signed with an e-signature.
Commercial Transactions: Contracts, proposals, order forms, and invoices between companies can be digitally approved with an e-signature. This accelerates business processes, reduces paper usage, and saves on archiving costs.
Banking and Finance: Banks have started to digitize transactions such as customer agreements and loan applications with e-signatures. This eliminates the need to visit a branch and allows transactions to be completed instantly.
Academic and Educational Fields: Universities can issue student documents, diploma supplements, and transcripts with an e-signature. This allows students to receive their documents more quickly and securely.

Comparison of Wet Signature vs. E-Signature: Why Is the E-Signature Superior?

The e-signature offers many advantages over a wet signature:

Security: The cryptographic structure of an e-signature makes forgery nearly impossible. A wet signature, on the other hand, can be easily imitated or forged. Furthermore, any changes made to an e-signed document are immediately noticeable. This is not possible with a wet-signed document.
Legal Validity: A qualified electronic signature is legally equivalent to a wet signature and can be used as evidence in court. The Turkish Electronic Signature Law No. 5070 clearly defines this validity.
Speed and Efficiency: The e-signature eliminates processes such as going to a physical location, waiting for a courier, or printing paper. Documents can be signed in seconds and sent anywhere in the world instantly. This accelerates business processes incredibly.
Cost and Environment: It significantly reduces paper, ink, shipping, and archiving costs. It also offers an environmentally friendly solution by reducing paper consumption.
Accessibility: The e-signature allows parties who are physically distant to sign legal documents without needing to meet in person. This provides a great convenience, especially for companies doing international business.

What Is Needed to Get an E-Signature? A Step-by-Step Guide

Getting an e-signature is a much easier process than you might think. Here is what you need to do:

Choose a Certificate Service Provider: First, you should choose an ECSP authorized by the Information and Communication Technologies Authority (BTK). There are many institutions in Turkey that provide this service.
Application: You should apply through the website of your chosen ECSP or through their authorized resellers. Your identity details, contact information, and purpose of application are usually requested.
Identity Verification: After the application, you need to go to a center authorized by the ECSP for identity verification or use a mobile identity verification service if available. In this step, your identity document (national ID card, passport, etc.) will be checked, and your biometric data may be collected.
Acquiring the E-Signature Device: After the identity verification process is complete, your e-signature device, consisting of a smart card or USB token, will be delivered to you.
PIN Definition and Preparation for Use: After receiving the device, you define a personal PIN (Personal Identification Number) for yourself. This PIN is used to ensure your security during signing processes. You install the necessary drivers by plugging the device into your computer, and you can then start using your e-signature.

Frequently Asked Questions

No, although their basic principles are similar, they are technically different. A mobile signature allows you to sign by verifying your identity via your mobile phone’s SIM card. An e-signature is usually used with a smart card or a USB token. Both are legally valid types of qualified electronic signatures.

E-signature certificates are usually valid for 1, 2, or 3 years. They need to be renewed after this period.

Your e-signature device’s PIN will be blocked after a certain number of incorrect attempts. In this case, you need to contact your ECSP to reset your PIN.

In Turkey, it can be mandatory for certain professional groups such as public employees, lawyers, and financial advisors. However, due to the ease of use and the advantages it offers, many private companies have also started to use e-signatures widely

The Key to the Digital Future

The e-signature is not just a signing tool; it is a turning point that makes the way we do business in a digitalizing world more secure, faster, and more efficient. Thanks to its legal validity, robust security infrastructure, and practical use, it has become an indispensable tool in both individual and corporate life. We hope this guide has helped to answer all the questions you had about e-signatures. Remember, the e-signature, as one of the most important steps in digital transformation, is a technology that will shape not only our present but also our future.