An electronic signature, or e-signature, is any electronic mark (sign, sound, symbol, etc.) used in place of a physical signature in signing a document or contract.

An electronic signature, or e-signature, is any electronic mark (sign, sound, symbol, etc.) used in place of a physical signature in signing a document or contract.

Electronic signatures have become widely adopted as an alternative to physical ones. As technology advances and allows legal work to become more digital, e-signatures have become a go-to solution for a wide array of services. While electronic signatures vary based on jurisdiction and country, there are several requirements in common, adopted across the board. E-signatures need to effectively identify the signatory without a doubt, and the person signing has to be the sole owner of the private key for the signature.  

With technological advancements, new forms of e-signatures are being created. One of the most popular alternatives to an e-signature is a digital signature. Digital signatures are not the same as electronic signatures, although the former term is often used to describe the latter technology. While e-signatures are simply digital marks representing a physical signature, digital signatures employ the powers of cryptography to ensure validity. Digital signatures are also extremely important in the cryptocurrency world. They allow you to verify that you are the private key owner without actually revealing any information about the key itself. 

Some e-signature services have started introducing cryptographic processes in order to boost their security. Some of the most common electronic signature providers include Adobe Sign and Hello Sign; however, with a growing demand for this technology over the past decade, more providers are entering the market. 

Electronic signatures have been recognized as a legally accepted replacement for a physical signature for a long time. In 1996, the United Nations published the UNCITRAL Model Law on Electronic Commerce, which contained several sections detailing the use of electronic signatures. This was a highly influential document, which sped up the global adoption and legalization of e-signatures. Today, new forms of electronic signatures are being introduced as technology advances and more applications become available. 

Biometric signatures are a popular type of e-signature. This type of signature relies on uniquely identifying physical qualities. For example, every time you unlock your phone with your fingerprint, you effectively use a biometric e-signature to verify that you have the right to use this phone. Face-identifying software also relies on biometric information to verify your identity, which means that your face can also serve as an electronic signature given the right software. 

With the rise of cryptographic and blockchain technology, electronic signatures are becoming more advanced and start taking on characteristics of digital signatures. While several years ago it might have been hard to implement cryptographic features for simply signing a document, today, digital signatures are becoming more widely used.