Non-deterministic time systems and methods

#This invention relates to an electronic system and method for generating a representation of non-deterministic time that can be used for, among other things, verifying that an event did not occur before a specific time.

#In the age of digital imaging and high-quality image-editing software, the maxim “Seeing is believing” is becoming increasingly out-dated. Nowadays, few cosmetic or clothing advertisements, billboards, magazine photos of celebrities, etc., are not digitally altered in some way. In fact, so many people have come to internalize a visually false portrayal of “reality” that at its 2011 meeting, the American Medical Association adopted a proposal calling on advertisers to develop guidelines to discourage the altering of photographs in a manner that could promote unrealistic expectations of appropriate body image. One attendee observed: “The appearance of advertisements with extremely altered models can create unrealistic expectations of appropriate body image. In one image, a model's waist was slimmed so severely, her head appeared to be wider than her waist.” The issue of altered images warping peoples' perceptions of some form of ideal has even reached the political level. In 2009, for example, various politicians in France proposed a law that would require a “warning” label on all advertising, press, political campaign, art photography and packaging images if an image has been retouched, in particular, digitally altered.

#Alteration of image content is only one aspect of the concerns involving image manipulation: In many cases, the time an image is created may also be essential information. For example, the time an image was first created can be the determining factor in the relevance of photographic or video evidence in a criminal trial. At present, in many jurisdictions, whether an image or sound recording is admissible as trial evidence is typically left to the discretion of the judge, and whether the admitted evidence proves the occurrence or non-occurrence of some event at a given time is often a question that the court—either the judge or jury or both—decides at least in part subjectively. This means that the accuracy of the determination is a function of the relative sophistication of the forger versus the court.

#FIG. 1 illustrates various layers of a generalized digital record verification and signing infrastructure, which further illustrates the generation of calendar values that can serve as the basis of non-deterministic time determination.

#FIG. 2 illustrates the verification infrastructure along with various data and computational structures maintained and computed within the different layers to obtain a calendar value at the end of a time interval.

#FIG. 3 shows a subset of FIG. 2 to illustrate a digital signature and recomputation of authentication values using the signature.

#In broad terms, this invention provides a method and various system implementations that generate a representation of non-deterministic time. The invention is described primarily with reference to examples that relate to a type of clock that can be used to mark captured representations of events so as to establish the time of capture in a way that greatly reduces the opportunity to forward-date altered representations. According to one preferred aspect, non-deterministic time is established based on an output of a keyless, distributed hash tree infrastructure, which may also optionally be used to authenticate the contents of the representation of the event as well. Before explaining the notion and use of non-deterministic time, such a keyless, distributed hash tree infrastructure is therefore described first.

#Distributed Hash Tree Infrastructure

#FIGS. 1 and 2 illustrate a distributed, keyless, hash tree-based digital record-authentication infrastructure such as is provided by Guardtime AS of Tallinn, Estonia. The general infrastructure has several different layers: a client layer 2000 comprising a number of client systems; a layer of gateways 3000; a layer including one or more aggregation systems 4000; and an uppermost layer 5000 that includes a “core”. Although FIG. 1 shows the various layers as being separate and distinct, some implementations of the main principles of the infrastructure might consolidate or do without some of the layers or might need to add additional layers for administrative or other purposes.