Lucent Technologies Inc.

At+t Corp.

Yissum Research Development Company of the Hebrew University of Jerusalem Ltd.

Michael Kendrick Reiter

Bjorn Markus Jakobsson

Stuart Gerald Stubblebine

Philip Douglas MacKenzie

Fabian Monrose

Matthew Keith Franklin

Philip L Bohannon

Susanne Gudrun Wetzel

Ben Jai

Robert M Arlein

Gregory Chockler

Dahlia Malkhi

Improved cryptographic techniques are provided by which a device that performs private key operations (e.g., signatures and/or decryptions), and whose private key operations are protected by a password, is immunized against offline dictionary attacks in case of capture by forcing the device to confirm a password guess with a designated entity or party in order to perform a private key operation, and by which the initiating device may dynamically delegate the password-checking function (i.e., confirmation of the password guess) from the originally designated entity or party to another designated entity or party.

Methods and apparatus for delegation of cryptographic servers for capture-resilient devices

A system for and method of implementing a backoff protocol and a computer network incorporating the system or the method. In one embodiment, the system includes: (1) a client subsystem that generates a request for access to a shared resource and (2) a server subsystem that receives the request, returns a LOCKED indicator upon an expectation that the shared resource is unavailable and otherwise returns a FREE indicator, the client subsystem responding to the LOCKED indicator by waiting before regenerating the request for the access.

Backoff protocols and methods for distributed mutual exclusion and ordering

Techniques are provided by which a device that performs private key operations (e.g., signatures or decryptions) in networked applications, and whose local private key is activated with, for example, a password or PIN, can be immunized to offline dictionary attacks in case the device is captured. The techniques do not assume tamper resistance of the device, but rather exploit the networked nature of the device, in that the device's private key operations are performed using a simple interaction with a remote server. This server, however, is untrusted, i.e., its compromise does not reduce the security of the device's private key unless the device is also captured, and need not have a prior relationship with the device. Techniques are also provided for supporting key disabling, by which the rightful owner of a stolen device can disable the device's private key even if the attacker already knows the user's password.

Methods and apparatus for providing networked cryptographic devices resilient to capture

Techniques and infrastructure are provided for supporting global customization. The invention enables persona profiles of user information to be maintained, and such persona profiles to be accessed by merchants. Via the persona abstraction, users control what information is grouped into a persona profile, and can selectively enable a merchant to read one of these profiles. The infrastructure of the invention employs a persona server that assists users in managing their personae. The infrastructure of the invention separates this from the profile databases at which persona profile information is stored, to eliminate any single point at which different persona profiles can be tied to the same user. Since merchants also have privacy concerns, the infrastructure of the invention provides a data protection model based on tainting, by which merchants can limit how the information they contribute can be exposed.

Methods and apparatus for providing privacy-preserving global customization

A software program is configured in accordance with a software aging process such that one or more files generated by the program are at least partially encrypted using a cryptographic key associated with a current time interval for which the files are generated. The cryptographic key may be a symmetric key used for both encryption and decryption operations, such that cryptographic key used for encryption in a given interval is also required to decrypt files encrypted during that interval. Periodic updates of the software program are provided to a legitimate user of the software program, with a given one of the updates including a different cryptographic key associated with a subsequent time interval. The cryptographic key associated with a particular one of the time intervals may be common to each of a set of legitimate copies of the software program that have received the corresponding version of the periodic update. The variation of the cryptographic keys from one interval to another discourages unauthorized use of the software program by deliberately requiring both legitimate and illegitimate users to request unusually frequent updates, thereby substantially increasing the tracing and prosecution risks borne by software pirates.

Software aging method and apparatus for discouraging software piracy

A repeatable cryptographic key is generated based on varying parameters which represent physical measurements. Locations within a share table, which locations store valid and invalid cryptographic shares, are identified as a function of received varying parameters. The share table is configured such that locations which are expected to be identified by legitimate access attempts contain valid cryptographic shares, and locations which are not expected to be identified by legitimate access attempts contain invalid cryptographic shares. The share table configuration may be modified based on prior history of legitimate access attempts. In various embodiments, the stored shares may be encrypted or compressed. A keystroke feature authentication embodiment uses the inventive techniques to implement an authentication system which authenticates based on an entered password and the manner in which (e.g. keystroke dynamics) the keystroke is entered. Another embodiment uses the inventive techniques to protect sensitive database information which is accessible using DNA measurements.

Generation of repeatable cryptographic key based on varying parameters

A name-to-target binding system generates certificates for use in authenticating a target key. In the system the certificate includes a first key. At least one attribute is assigned to the first key. A liability value is assigned to the combination of the first key and the at least one attribute. The system includes a second key used to sign a combination of the first key, the at least one attribute and the liability value wherein the second key is associated with the insurer agreeing to be liable for the liability value.

Method for providing authentication assurance in a key-binding system

A method and apparatus for fairly exchanging documents. A first document is shared between principal Y and third party Z. A second document is shared between principal X and third party Z. Z verifies that the sharing of the first and second documents has been performed correctly without Z understanding either document. If verified, Z sends its shares of the first and second documents to Y and X, respectively. X and Y verify that Z's shares are authentic.

Method and apparatus for simultaneous electronic exchange using a semi-trusted third party

The apparatus and method of the present invention provide secure auction service for use in a network having servers and bidding terminals. The auction service makes transactions among servers and bidding terminals subject to a distributed protocol. The distributed protocol distributes submitted bids among the multiple servers, closes a bidding period, verifies validity of monetary value of each submitted bid by utilizing said distributed protocol and determines a winning bidder.

Secure auction systems

Authenticating the source of a message in a large distributed system can be difficult due to the lack of a single authority that can tell for whom a channel speaks. This has led many to propose the use of a path of authorities, each able to authenticate the next, such that the first authority in the path can be authenticated by the message recipient and the last authority in the path can authenticate the message source. The present invention uses multiple ones of such paths, no two of which share a common authority, to provide independent confirmation of the message source. As the problem of finding a maximum set of such paths of bounded length in a graph-theoretic framework can be shown to be NP-hard, the present invention includes approximation algorithms for this problem. The present invention also includes a PathServer for PGP, a service for finding maximum sets of such paths to support authentication in PGP-based applications.

Growing community of inventors

Raritan, NJ, United States of America

Michael Kendrick Reiter