Digital Signature

Full Title or Meme

A Digital Signature is a string of bits created by a cryptographic process that is extremely difficult to create without access to a Private Key.

Nearly all of our digital lives depends on the ability to make a mark that can be known to have been make by the Subject.
A (sem-)legal definition is a mark or sign made by an individual on an instrument or document to signify knowledge, approval, acceptance, or obligation.^[1]
The term signature is generally understood to mean the signing of a written document with one's own hand. However, it is not critical that a signature actually be written by hand for it to be legally valid. It may, for example, be typewritten, engraved, or stamped. The purpose of a signature is to authenticate a writing, or provide notice of its source, and to bind the individual signing the writing by the provisions contained in the document.
Because a signature can obligate a party to terms of a contract or verify that the person intended to make a last will and testament, the law has developed rules that govern what constitutes a legally valid signature. The Internet and other forms of telecommunication have created the need to transact legally binding agreements electronically. Almost all states have passed laws that recognize the validity of Digital Signatures."

Not all Subjects are legal entities, so the meaning of the signature would be unclear.
Public/Private Key technology is itself subject to attack and so the meaning of a secure public key technology is subject to revision from time to time as technology advances.
Technologists somehow got the idea that they could define what a signature means. This is demonstrably untrue.
The contents of the document signed are a key determinate to what a signature means. This cannot be changed by wishful thinking.
- For example the level of assurance of an identity statement carries information about the live of verification that was applied by the signatory.

Samuel M Smith crated a taxonomy of trust carried by a signature. This is helpful for technologists, but, in and of itself, has no impact on the meaning of a signature.