QES

Qes is an acronym used in several technical and academic domains. In many contexts it refers to the Qualified Electronic Signature (QES) under European Union eIDAS rules, while in physics it is common shorthand for quasi-elastic scattering (QES). The term can also appear as an abbreviation for other domain-specific concepts depending on context.

Qualified Electronic Signature. Under the EU eIDAS Regulation, a QES is an electronic signature created by a qualified electronic signature creation device and based on a qualified certificate issued by a trusted qualification service provider. A QES has the equivalent legal effect of a handwritten signature in all EU member states, provided the signatory’s identity has been verified. The security requirements typically include identity verification, secure storage of keys, and tamper-evident signatures. QES is widely used for cross-border transactions, legal documents, government services, and financial operations, where non-repudiation and integrity are essential.

Quasi-elastic Scattering. In physics, QES denotes quasi-elastic scattering, a process in which the collision rearranges energy or momentum with little excitation of internal states. It is distinguished from purely elastic scattering and from inelastic scattering where internal degrees of freedom change significantly. Quasi-elastic scattering is analyzed in nuclear and particle experiments by measuring cross sections and angular distributions, often to extract information about nuclear structure, reaction mechanisms, or form factors.

Other uses. Beyond these domains, Qes may appear as an acronym in business, technology, or as a surname or place name in various languages. Because Qes is context-dependent, additional information is usually required to determine the intended meaning.