AdvisorAdvanced electronic signature

Electronic signatures have many advantages, including increasing the efficiency of processes and the conversion of contracts. However, not all electronic signatures are the same. There are a total of three different types of electronic signatures, which differ in their technical complexity and legal regulatory acceptance. This guide explains what an advanced electronic signature (so-called AES) is and how it differs from the other electronic signatures.

What is an advanced electronic signature?

Since digital signing is not always secure, various technical procedures have been developed to make paperless signing more secure. The advanced electronic signature is one of the three different types of electronic signature. Due to its complexity, it has a high level of security and is therefore often used for informal agreements and standard contracts that do not require the written form.

Significance of the electronic certificate

An electronic certificate is an integral part of the advanced signature. With it, the signature verification data can be assigned to a person to confirm his or her identity.

Requirements of an advanced electronic signature

According to Section 4, Article 26 of the Regulation on Electronic Identification and Trust Services for Electronic Identification (eIDAS), an advanced electronic signature must meet the following requirements:

  1. It is uniquely assigned to the signatory.
  2. It enables the identification of the signatory.
  3. It is created using electronic signature creation data that the signatory can use with a high degree of confidence under his or her sole control.
  4. It is linked to the signed data so that you can detect any subsequent alteration

Advanatages of an advanced electronic signature

Due to security concerns, most people still tend to use paper when concluding a contract and other legally binding processes. However, paper-based processes cause often higher costs and lower efficiency. For example, if you want to send a contract by post, you must print it first, sign it by hand, put it in an envelope and bring it to the post office. This process can take several days and is very cost consuming.

By using the advanced electronic signature instead of the traditional signature on paper, you can simplify and shorten this processes immensely. in addition, this process becomes more efficient, reduces costs and the conerverion of contracts increases. Another important advantage is the lower risk of security because you can detect subsequent changes to the contract data, when you have already signed a digital document with an advanced electronic signature.

Differences to simple and qualified electronic signature

In contrast to the advanced signature, the simple electronic signature has only a low level of complexity. This means it has a lower security level than the advanced signature.

The use of the advanced electronic signature requires encryption software. This is not necessary with the simple signature. Here, it is sufficient to place the signature on the PDF document, e.g. by using tablet pen or inserting an image of the scanned signature. Sending the PDF-file is also unencrypted.

The advanced electronic signature is much more secure because it verifies the origin and authenticity of the signature and thus excludes the possibility of forgery. The use of digital security keys and security certificates makes this possible.


The qualified electronic signature is the most secure electronic signature and thus has a higher probative value than the advanced electronic signature. Only the qualified electronic signature is equivalent to the handwritten signature by law and thus fulfils the legal form requirement for concluding contracts.

Both qualified and advanced signature use the same technical mechanisms. In the case of the qualified signature, however, you can validate the identity and authenticity of the signatory, it is based on a qualified electronic certificate and a signature key that must be available in a certified electronic security unit.

Technical requirements

Although the technical processes of the advanced electronic signature are complex, the technical requirements for the user are limited. All you need is a suitable software in which you can sign a digital document with an advanced electronic signature.

This programme creates a public verification key and a signature key with which the recipient can verify the authenticity of the signature.

Legal validity and probative value of advanced electronic signature

Since the advanced electronic signature is very secure due to its complexity, its probative value in court is relatively high. Nevertheless, the advanced signature is not comparable to the probative force and legal validity of a handwritten signature. For example in Germany,  according to section 127 (3) BGB, an advanced electronic signature is sufficient if this has been contractually agreed in advance.

Since the advanced electronic signature is relatively secure, it is often used in form-free agreements and standard contracts. An example of this is a PGP-signed e-mail.

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