摘要:
A system and method for implementing a multi-step challenge and response test includes steps or acts of: using an input/output subsystem for presenting a series of challenges to a user that require said user to correctly solve each challenge before a next challenge is revealed to the user; receiving the user's response to each challenge; and submitting a last response in the series of challenges to a server for validation. The method further includes: using a processor device configured to perform for each challenge in the series of challenges: internally validating the response by comparing the user's response to a correct response; and using the user's response, decrypting the next challenge to reveal the next challenge; wherein the next challenge remains obfuscated until a previous challenge is correctly solved.
摘要:
An image CAPTCHA having one or more images, a challenge, and a correct answer to the challenge is constructed by selecting the one or more images from a plurality of candidate images based at least in part on each image's public information and private information. The private information of each of the images is accessible only to an entity responsible for constructing the CAPTCHA. Optionally, the one or more images are selected further based on the specific type of the CAPTCHA to be constructed.
摘要:
A method of generating a time managed challenge-response test is presented. The method identifies a geometric shape having a volume and generates an entry object of the time managed challenge-response test. The entry object is overlaid onto the geometric shape, such that the entry object is distributed over a surface of the geometric shape, and a portion of the entry object is hidden at any point in time. The geometric shape is rotated, which reveals the portion of the entry object that is hidden. A display region on a display is identified for rendering the geometric shape and the geometric shape is presented in the display region of the display.
摘要:
Techniques are described herein for generating CAPTCHAs that include overlapped characters, projections on virtual three-dimensional (3D) surfaces, and/or virtual 3D objects. A CAPTCHA is a type of challenge-response test that a content provider may present to users for authorizing the users to access content that the content provider hosts. For example, when a user attempts to access content, a CAPTCHA may be generated in accordance with one or more of the techniques described herein and provided to the user. The user may be asked to identify characters that overlap in the CAPTCHA, characters that are projected on a virtual 3D surface, and/or a designated virtual 3D object, so that the user may be authorized to access the content. The user may enter the characters and/or select the designated virtual 3D object that is identified in the CAPTCHA using an input device, such as a keyboard, touch screen, pointing device, etc.
摘要:
A method of generating a time managed challenge-response test is presented. The method identifies a geometric shape having a volume and generates an entry object of the time managed challenge-response test. The entry object is overlaid onto the geometric shape, such that the entry object is distributed over a surface of the geometric shape, and a portion of the entry object is hidden at any point in time. The geometric shape is rotated, which reveals the portion of the entry object that is hidden. A display region on a display is identified for rendering the geometric shape and the geometric shape is presented in the display region of the display.
摘要:
Techniques are described herein for providing a marketplace for CAPTCHA developers. A CAPTCHA is a type of challenge-response test that a content provider may present to users for authorizing the users to access content that is hosted by the content provider. CAPTCHA developers may propose CAPTCHAs for testing in the marketplace. A server is configured to provide instances of proposed CAPTCHAs to users along with instances of reference CAPTCHAs that have known difficulties to determine the relative difficulties of the proposed CAPTCHAs for the users. The server may determine a reward to be provided to a developer of a proposed CAPTCHA based on a difficulty that the predetermined automated systems encounter when they attempt to solve the proposed CAPTCHA and an ease with which the users solve the proposed CAPTCHA. The server may determine rewards to be provided to developers of predetermined automated systems that solve the proposed CAPTCHAs.
摘要:
Method, system, and programs for computing similarity. Input data is first received from one or more data sources and then analyzed to obtain an input feature vector that characterizes the input data. An index is then generated based on the input feature vector and is used to archive the input data, where the value of the index is computed based on an improved Johnson-Lindenstrass transformation (FJLT) process. With the improved FJLT process, first, the sign of each feature in the input feature vector is randomly flipped to obtain a flipped vector. A Hadamard transformation is then applied to the flipped vector to obtain a transformed vector. An inner product between the transformed vector and a sparse vector is then computed to obtain a base vector, based on which the value of the index is determined.
摘要:
Embodiments of the present inversion relate to a two-pass compression scheme that achieves compression performance on par with existing methods while admitting individual message decompression. These methods provide both storage savings and lower end-user latency. They preserve the advantages of standard text compression in exploiting short-range similarities in data, while introducing a second step to take advantage of long-range similarities often present in certain types of structured data, e.g. email archival files.
摘要:
Embodiments of the present inversion relate to a two-pass compression scheme that achieves compression performance on par with existing methods while admitting individual message decompression. These methods provide both storage savings and lower end-user latency. They preserve the advantages of standard text compression in exploiting short-range similarities in data, while introducing a second step to take advantage of long-range similarities often present in certain types of structured data, e.g. email archival files.
摘要:
Method, system, and programs for computing similarity. Input data is first received from one or more data sources and then analyzed to obtain an input feature vector that characterizes the input data. An index is then generated based on the input feature vector and is used to archive the input data, where the value of the index is computed based on an improved Johnson-Lindenstrass transformation (FJLT) process. With the improved FJLT process, first, the sign of each feature in the input feature vector is randomly flipped to obtain a flipped vector. A Hadamard transformation is then applied to the flipped vector to obtain a transformed vector. An inner product between the transformed vector and a sparse vector is then computed to obtain a base vector, based on which the value of the index is determined.