How it works?

If somebody wants to prove that a message was created by him, he can create a digital signature on the message so that others can verify it.

Digital signature schemes typically use asymmetric cryptosystems (such as RSA or ECC) and hash functions. Check this article on cryptography if you want a low-down on these terms.

Digital signatures are widely used today in the business and financial industry, e.g. for authorising bank payments, exchanging signed electronic documents, signing transactions in the public blockchain systems, signing digital contracts, and in many other scenarios.

How Digital Signatures Work

Let’s use the underground love between Alice and Bob again – our favourite crypto couple featuring in many of our articles.

Alice finally wants to break up with Bob since she cannot tolerate their secret love anymore. She has written the message ‘Let’s break up’ (which translated into ‘9394’ in the ‘Nerd Planet’). She’s afraid that Bob may think that the message is not truly from her (maybe Bob’s wife discovered their relationship and stole Alice’s account to write the message). Therefore she would like to attach the message together with a digital signature and send it to Bob so that Bob would believe that the message is coming from her.

Using the example above, we hope the reader can understand what digital signatures are used for and why they can ensure a message is truly coming from the message sender. Digital signatures cleverly combine symmetric and asymmetric cryptography with hash functions, and the invention has enabled a wide range of applications that require secure communication and identity verification.