The web service may provide the second pantograph and/or a link to the second void pantograph so the first void pantograph may be authenticated. The second void pantograph facilitates the authentication of the first void pantograph, and hence the item by making the second void pantograph available to the computing device. The web service, in turn, utilizes the identifier to further identify the second void pantograph. The identifier is transmitted for a web service to identify the corresponding void pantograph (e.g., the second void pantograph). The examples scan the machine-readable data related to the item, the machine-readable data contains an identifier which is unique to a second void pantograph. As such, the first void pantograph may be suitable for hiding in a background of a document, package, the machine-readable data, or other surface for being able to authenticate the item. The item may include a document, label, packaging, or other sort of material which is associated with a first void pantograph and machine-readable data. The void pantograph is an image which includes a pattern that becomes visible upon scanning and/or photocopying the void pantograph. To address these issues, examples disclosed herein provide a security mechanism of using a void pantograph as a means of detecting if an item is counterfeit. For example, if there is a particular phrase such as “void,” the counterfeiter may be able to easily reproduce this phrase. Additionally, other counterfeit mechanisms may be easier for a counterfeiter to reproduce. It may be difficult for the user to detect which hologram may be the genuine hologram. For example, a drug bottle may include a hologram or other security mechanism for the user to detect if the bottle is genuine. DETAILED DESCRIPTIONĬounterfeit items may not be readily detectable as it may be infeasible for a user to differentiate a genuine item from a counterfeit item. 7 is a block diagram of an example computing device with a processor to execute instructions in a machine-readable storage medium for obtaining an identifier from a first void pantograph and identifying a second void pantograph for facilitating an authentication or denial of authentication of the first void pantograph.
6 is a block diagram of an example method executable by a computing device, to scan machine-readable data including a barcode, label, quick response (QR) code, stock keeping unit (SKU) code for transmitting an identifier and receiving a second void pantograph for authentication of a first void pantograph at the computing device andįIG. 5 is flowchart of an example method, executable by a computing device, to obtain an identifier from machine-readable data and transmitting the identifier across a network to a server for identification of a second void pantograph for authenticating a first void pantograph įIG. 4 is a flowchart of an example method, executable by a server, to identify a second void pantograph by retrieving the second void pantograph from a database or generating the second void pantograph from an identifier, the method facilitates an authentication of a first void pantograph by transmitting the second void pantograph įIG. 3 is a flowchart of an example method, executable by a server, to receive an identifier associated with a first void pantograph for identifying a second void pantograph, the second void pantograph facilitates an authentication of the first void pantograph įIG. 2 is a data diagram for example communications between a computing device and a web service for authenticating a first void pantograph through receipt of a second void pantograph įIG. 1B is a block diagram illustrating example patterns from a first void pantograph and a second void pantograph which are used to validate the first void pantograph, accordingly įIG. 1A is a block diagram of an example system including a computing device and a web service, the computing device processes machine-readable data to obtain an identifier for identification of a second void pantograph which is used to invalidate the authentication of a first void pantograph at the computing device įIG. The following detailed description references the drawings, wherein:įIG. In the accompanying drawings, like numerals refer to like components or blocks. These patterns are invisible to the untrained human eye, but visibly stand out when the document is scanned and/or photocopied. In security printing, a void pantograph refers to a method of making copy-evident patterns in a background of a document.