An electronic signature, or e-signature, is any electronic mark (sign, sound, symbol, etc.) used in the palace 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.
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.