Regarding the Validity of Biometric Signature under Turkish Law and Its Use in Transactions Subject to Written Form Requirements

Biometric signature, which constitutes a subcategory of electronic signatures, is defined as a signature created by signatories using certain biometric data on a dedicated tablet/pad and generally obtained by irreversibly linking such data to the signed document.

Although the unique characteristics of biometric signatures, including personal biometric features and dynamic characteristics such as the pressure applied during signing and the angle of writing, provide a sufficient level of security, the complex structure of biometric signatures has led to discussions regarding their legal nature and evidentiary value.

Within the scope of Turkish legislation, the main point of discussion regarding the evidentiary value of biometric signatures is whether biometric signatures may replace handwritten signatures, particularly in transactions subject to mandatory form requirements.

Below, we present a summary of the main questions and answers regarding the nature, legal position, and validity of biometric signatures under Turkish law, considering that biometric signatures consist of characteristics unique to an individual and therefore cannot be changed or forgotten by that individual.

A. Nature and Areas of Use of Biometric Signature

QuestionAnswerExplanationCompared to a wet signature, is special preparation required to create a biometric signature?NoA biometric signature is created effortlessly through devices such as tablets, mobile phones, or computers. It is a “handwritten” signature created on electronic devices where unique dynamic characteristics of the individual, such as the amount of pressure applied during signing, writing angle, pen speed and acceleration, formation of letters, direction of the signature, and similar characteristics, are recorded.Do technological developments play an effective role in the widespread use of electronic signing of documents?YesAs a natural consequence of innovations brought by technological developments and the rapid impact of digitalized commercial life on daily activities, electronic signing of documents has become a necessity. Particularly today, due to the acceleration of digitalization and the need for technological solutions arising from the COVID-19 pandemic, signatures serving the same purpose as wet signatures are increasingly preferred through specially designed methods and technological devices.Has the widespread adoption of biometric signatures increased the need for legal regulations in this field?YesThe digitalization of commercial life, the need for electronic signing of documents, and the ability to perform transactions electronically without requiring wet signatures have made legal regulations in this area necessary. To meet this need, electronic signatures were first introduced into Turkish law through the Electronic Signature Law No. 5070 (“ESL”), which entered into force on 24 July 2004. The ESL was prepared by taking into consideration the European Union Electronic Signature Directive No. 1999/93/EC, the Electronic Commerce Directive No. 2000/31, and the model laws and fundamental rules prepared by UNCITRAL regarding electronic commerce and electronic signatures. [1]

B. Evaluation of Biometric Signature under the Law of Obligations

QuestionAnswerExplanationIs it mandatory for contracts subject to written form requirements to be signed by handwritten signature?NoThe written form requirement is regulated under the Turkish Code of Obligations No. 6098 (“TCO”), which constitutes the fundamental legislation governing transactions creating obligations between parties. Article 14 of the TCO primarily requires the signature of the parties assuming obligations in transactions subject to written form requirements. The same provision further states that, unless otherwise provided by law, texts sent and stored with a secure electronic signature shall replace the written form requirement. Accordingly, unless there is a specific legal provision, parties may satisfy the written form requirement through a secure electronic signature.Is there any regulation regarding biometric signatures under the Turkish Code of Obligations?NoArticle 15 of the TCO stipulates that a signature must be handwritten by the person assuming the obligation and that a secure electronic signature shall produce all legal consequences of a handwritten signature. However, there is no explicit regulation regarding biometric signatures. Electronic signature is defined under Article 3(b) of the ESL as electronic data that is attached to another electronic data or logically associated with electronic data and used for authentication purposes. Although the definition and characteristics of electronic signatures overlap with certain characteristics of biometric signatures, biometric signatures are not expressly regulated under the provisions of the TCO.

B. Evaluation of Biometric Signature under the Law of Obligations (Continued)

QuestionAnswerExplanationDo documents signed with an electronic signature produce all legal consequences of a handwritten signature under the provisions of the Turkish Code of Obligations?NoA secure electronic signature is defined under Article 4 of the Electronic Signature Law (“ESL”) as an electronic signature that is created through a secure electronic signature creation device solely under the control of the signatory and enables the identification of the signatory based on a qualified electronic certificate. Since the ESL requires a secure electronic signature to be created based on an electronic certificate, electronic signatures that do not fall within the category of secure electronic signatures do not produce all legal consequences of handwritten signatures.

Although the ESL follows an approach parallel to the Regulation on electronic identification and trust services of the European Union, namely the Electronic Identification and Trust Services Regulation (“eIDAS”), which was enacted in 2014 to meet current technological requirements, the electronic signature levels defined under eIDAS do not have direct equivalents under the ESL, as the ESL is based on the former Electronic Signature Directive No. 1999/93/EC. [2]

However, similar to the ESL, the eIDAS provisions stipulate that an electronic signature becomes qualified when it is provided by a qualified trust service provider and meets the required criteria.

Within this scope, when the provisions of the ESL and eIDAS are evaluated together, it may be concluded that electronic signatures having characteristics similar to biometric signatures do not produce all legal consequences of handwritten signatures, unlike secure electronic signatures.

C. Evaluation of Biometric Signature under the Code of Civil Procedure

QuestionAnswerExplanationCan documents containing biometric signatures be accepted as written evidence under the Code of Civil Procedure No. 6100 (“CCP”)?NoPursuant to Article 200 of the CCP, legal transactions exceeding a certain amount or value at the time they are executed must be proven by a written document. Article 205 of the CCP regulates that ordinary written documents acknowledged before the court or deemed to have originated from the person against whom they are asserted shall constitute conclusive evidence unless proven otherwise, and that electronic data created with a secure electronic signature in accordance with the applicable procedures shall have the status of a written document.

Considering that, under current legislation, the only electronic signature capable of satisfying formal requirements in legal transactions is a secure electronic signature, documents signed with biometric signatures will not be accepted as written evidence within the scope of the CCP.

QuestionAnswerExplanationAre documents signed with biometric signatures suitable for proving the existence of a right?YesAlthough documents signed with biometric signatures are not considered conclusive evidence under the CCP, documents containing biometric signatures, which fall within the scope of simple electronic signatures, may be accepted as “prima facie evidence” in legal proceedings.

Under the CCP, prima facie evidence is defined as a document that does not fully prove the alleged legal transaction but makes such legal transaction probable and has been issued or sent by the person against whom it is asserted or by their representative.

Within this framework, although documents signed with biometric signatures are not entirely sufficient to prove the relevant legal transaction, they may demonstrate the likelihood of such transaction and, as an exception to the rule requiring proof by written document, enable the existence of the right to be proven through witness testimony.

D. Evaluation of Biometric Signature under the Law on Protection of Personal Data

QuestionAnswerExplanationCan biometric signatures be considered within the exception applicable to handwritten wet signatures according to the decisions of the Personal Data Protection Board?NoThe Personal Data Protection Board (“Board”) evaluated biometric signatures in its decision dated 27 August 2020 and numbered 2020/649. Although certain similarities exist between biometric signatures and handwritten wet signatures, the Board concluded that biometric signatures cannot be considered equivalent to wet signatures due to the fact that biometric signature solutions have different structural characteristics and are defined within a specific technological framework.

The Board evaluated that the scope of the concept of “signature” regulated under the Turkish Code of Obligations includes traditional signatures and secure electronic signatures. Although secure electronic signatures and traditional signatures are considered to have the same legal consequences, the legislator regulated both traditional signatures and secure electronic signatures separately.

Therefore, interpreting the relevant provisions of the Turkish Code of Obligations as covering biometric signatures would be contrary to the principle of proportionality. [4]

QuestionAnswerExplanationHas the Personal Data Protection Board imposed certain conditions for obtaining biometric signatures?YesThe Board stated that biometric signatures are created by signatories using certain biometric data on a dedicated tablet/pad and generally obtained by irreversibly linking such data to the signed document.

Pursuant to Article 6 of the Law on Protection of Personal Data No. 6698 (“LPPD”), biometric data is considered a special category of personal data, and biometric data may only be processed without explicit consent where such processing is expressly provided for by law.

In addition, the Board considers that where biometric data processing is provided for by law, the relevant legal provision must be sufficiently clear and leave no room for doubt.

Since the provisions of the Turkish Code of Obligations regarding the form of contracts do not expressly regulate the processing of biometric data, the Board stated that biometric signatures may only be obtained where the processing is explicitly provided for by law or where explicit consent is obtained from the relevant individuals and the necessary information notice is provided.

E. Comparison of Biometric Signature with Wet Signature

QuestionAnswerExplanationDo biometric signatures and wet signatures have similar functions?YesThe most important common feature of biometric signatures and wet signatures is that both are created “by the handwriting of the relevant person.” However, as also addressed under eIDAS regulations, they are not identical in terms of all their functions.

A traditional wet signature made manually on paper relies on the visual appearance of the signature and considers its static or geometric characteristics. A biometric signature, on the other hand, considers dynamic characteristics that can be described as the manner in which the signature is created.

The most significant difference between the two types of signatures is that a wet signature is manually placed on paper, whereas a biometric signature is created on a tablet, computer, or mobile phone.

When a person denies having created either a wet signature or a biometric signature, signature examination shall be conducted by forensic police laboratories or forensic medicine institutions.

QuestionAnswerExplanationAre there similarities between the analysis of biometric signatures and handwritten signatures?YesForensic police laboratories or forensic medicine institutions are capable of identifying the person to whom a handwritten signature belongs, whether it appears on a paper document or an electronic document, by using relevant technologies and standards. [5]

Within this scope, to the extent that a signature is created by an individual's handwriting, there is no significant difference between signing a paper document and signing an electronic document.

Furthermore, since a biometric signature is technically a handwritten signature created on an electronic screen, it should be considered within discussions regarding its validity that biometric signatures provide significant advantages in terms of evidentiary law, as they are created through dynamic characteristics that are difficult to copy and may possess stronger evidentiary value than wet signatures.

QuestionAnswerExplanationIs it possible to evaluate a biometric signature as a secure electronic signature?YesWhen the provisions of the ESL and eIDAS are evaluated together, although no definitive determination can be made regarding the legal nature of biometric signatures since biometric signatures relating to the unique dynamic characteristics of the signatory are not expressly regulated under the ESL, biometric signatures may be considered secure electronic signatures within the scope of eIDAS provisions.

However, although biometric signatures may be legally valid under eIDAS regulations, they cannot be considered to have full legal validity under eIDAS since they are not regarded as equivalent to handwritten signatures.

This full validity may be achieved through amendments to the ESL by adopting Server Signing technology, which enables secure electronic signatures to be created through servers rather than requiring the use of user-specific tokens (conventional electronic signatures) or mobile signature applications based on SIM cards.

It should be noted that Server Signing technology may contribute to the rapid expansion of electronic signatures by eliminating dependency on intermediary hardware devices. [6]

Conclusion

In conclusion, although biometric signatures that do not fall within the scope of secure electronic signatures under current Turkish legislation do not produce the same legal consequences as handwritten signatures for transactions subject to written form requirements under the Turkish Code of Obligations, biometric signatures may be considered valid signatures for transactions that are not subject to written form requirements and are not restricted by law.

The innovations introduced by technological developments and the increasing use of electronic signatures in digitalized commercial life have increased the need for legal regulations in this field.

However, due to the fact that secure electronic signatures under the ESL must currently be used through hardware-based systems and individuals seek to complete transactions quickly, the use of secure electronic signatures has not become sufficiently widespread.

If amendments are made to the ESL by the Information and Communication Technologies Authority to include electronic signature types such as biometric signatures within the scope of secure electronic signatures, biometric signatures will easily satisfy the written form requirement and their use will become widespread.

Submitted for your information and evaluation.

References

[1] TTBB Journal, Issue No. 63, 2006, Electronic Signature and Legal Regulations Regarding Electronic Signatures, p. 119.

[2] Electronic Signature Levels, Peer-Reviewed Articles, Information Management, Issue No. 2, 2019, p. 136. Access Date: 24.02.2022
https://dergipark.org.tr/en/download/article-file/899520

[3] Assistant Professor Dr. Leyla Keser Berber, “I Sign, Therefore I Exist” Digital Signature, Legal Regulations Regarding Digital Signature, Legal Value of Digitally Signed Electronic Documents, p. 548.

[4] Personal Data Protection Board Decision:
https://www.kvkk.gov.tr/Icerik/6815/2020-649

[5] Istanbul Bilgi University Institute of Information and Technology Law, Biometric Signature and Its Position Regarding the Written Form Requirement under the Turkish Code of Obligations and Signature Requirement under the Code of Civil Procedure
https://itlaw.bilgi.edu.tr/media/document/2019/08/biyometrik-imza.pdf

[6] Istanbul Bilgi University Institute of Information and Technology Law, Biometric Signature and Its Position Regarding the Written Form Requirement under the Turkish Code of Obligations and Signature Requirement under the Code of Civil Procedure
https://itlaw.bilgi.edu.tr/media/document/2019/08/biyometrik-imza.pdf