"Legal instrument" is a legal term of art that is used for any written legal document such as a property deed, a will, an Act of Parliament or a law passed by a competent legislative body in municipal (domestic) or international law. Many legal instruments were written under seal by affixing a wax or paper seal to the document in evidence of the legal exchange value of the document (formerly used as a form of consideration in contract law), today most jurisdictions have done away with the requirement of documents being under seal in order to give them legal effect.
Electronic legal documents
Legal instruments have undergone a process of dematerialisation as it is now possible to sign digital documents, have them date and time stamped, or otherwise verified through various schemes of encryption and document authentication.
In particular, the United States Congress enacted a stature in mid 2000 specifying that no court could thereafter fail to recognize a contract simply because it was digitally signed. The law is very permissive, making essentially any electronic character in a contract sufficient. No restriction is made to signatures which are adequately cryptographically tied to both the document text (see message digest) and to a particular key whose use should be restricted to certain persons (eg, the alleged sender).
Several states had already enacted laws on the subject of electronic legal documents and signatures before the U.S. Congress had acted, including Utah, Washington, and California to name only a few of the earliest. They vary considerably in intent, coverage, cryptographic understanding, and effect.
Several other nations and international bodies have also enacted statutes and regulations regarding the validitiy and binding nature of digital signatures. To date, the variety (and inadequacy) of the definitions used for digital signatures (or electonic signatures) have produced a legal and contractual minefield for those who may be considering on relying on the legality and enforceability of digitally signed contracts in any of many jurisdictions. Adequate legislation informed by the latest in cryptographic technology remains an elusive goal. That it has been achieved (in any jurisdication) is an illusion.
