Xerox Corporation

University of California

Leland Stanford Junior University

Other

Matthew K Franklin

Thomas A Berson

Teresa F Lunt

R Drews Dean

Diana Kathryn Smetters

Dan Boneh

Mark Jeffrey Stefik

Bernardo A Huberman

Daniel H Greene

Douglas N Curry

David L Hecht

Alan G Bell

Robert Thomas Krivacic

Tad H Hogg

Todd A Cass

Dirk Balfanz

Glenn Edward Durfee

Ralph C Merkle

Thomas M Breuel

R Drew Dean

Jessica N Staddon

Sara More

Michael Malkin

A method and system for encrypting a first piece of information M to be sent by a sender [] to a receiver [] allows both sender and receiver to compute a secret message key using identity-based information and a bilinear map. The sender uses a bilinear map to encrypt a message M, producing ciphertext V to be sent from the sender [] to the receiver []. The receiver [] uses the bilinear map to decrypt V and recover the original message M. According to one embodiment, the bilinear map is based on a Weil pairing or a Tate pairing defined on a subgroup of an elliptic curve. Also described are several applications of the techniques, including key revocation, credential management, and return receipt notification.

Systems and methods for identity-based encryption and related cryptographic techniques

A method and system for encrypting a first piece of information M to be sent by a sender [to a receiver [allows both sender and receiver to compute a secret message key using identity-based information and a bilinear map. In a one embodiment, the sender [computes an identity-based encryption key from an identifier ID associated with the receiver [. The identifier ID may include various types of information such as the receiver's e-mail address, a receiver credential, a message identifier, or a date. The sender uses a bilinear map and the encryption key to compute a secret message key g, which is then used to encrypt a message M, producing ciphertext V to be sent from the sender [to the receiver [together with an element rP. An identity-based decryption key dis computed by a private key generator [based on the ID associated with the receiver and a secret master key s. After obtaining the private decryption key from the key generator [, the receiver [uses it together with the element rP and the bilinear map to compute the secret message key g, which is then used to decrypt V and recover the original message M. According to one embodiment, the bilinear map is based on a Weil pairing or a Tate pairing defined on a subgroup of an elliptic curve. Also described are several applications of the techniques, including key revocation, credential management, and return receipt notification.

A method and system for encrypting a first piece of information M to be sent by a sender [] to a receiver [] allows both sender and receiver to compute a secret message key using identity-based information and a bilinear map. In a one embodiment, the sender [] computes an identity-based encryption key from an identifier ID associated with the receiver []. The identifier ID may include various types of information such as the receiver's e-mail address, a receiver credential, a message identifier, or a date. The sender uses a bilinear map and the encryption key to compute a secret message key g, which is then used to encrypt a message M, producing ciphertext V to be sent from the sender [] to the receiver [] together with an element rP. An identity-based decryption key dis computed by a private key generator [] based on the ID associated with the receiver and a secret master key s. After obtaining the private decryption key from the key generator [], the receiver [] uses it together with the element rP and the bilinear map to compute the secret message key g, which is then used to decrypt V and recover the original message M. According to one embodiment, the bilinear map is based on a Weil pairing or a Tate pairing defined on a subgroup of an elliptic curve. Also described are several applications of the techniques, including key revocation, credential management, and return receipt notification.

A system, method and article of manufacture are provided for pricing a cryptographic service. A request for a cryptographic service is received. An identification is made of one or more of a computational burden required to perform the cryptographic service, a privacy level of the cryptographic service, and/or a speed of performing the cryptographic service. A price of the cryptographic service is determined based on the computational burden, privacy level, and/or speed. A method is also provided for pricing a cryptographic service based on a compactness of a cryptographic message. A request for encrypting a message is received. The message is encrypted and is also compressed during the encryption. An amount of compression of the message is determined. A price of the encryption is determined based on the amount of compression.

System, method and article of manufacture for determining a price of cryptograph IC services based on a computational burden thereof

Systems and methods that allow the formation and distribution of session keys amongst a dynamic group of users communicating over an unreliable, or lossy, network. The systems and methods according to this invention allow an intermediate session key contained in an intermediate key distribution broadcast to be determined by receiving a preceding key distribution broadcast that precedes the intermediate key distribution broadcast, the preceding key distribution broadcast including a first portion of the intermediate session key; receiving a subsequent key distribution broadcast that follows the intermediate key distribution broadcast, the subsequent key distribution broadcast including a second portion of the intermediate session key that is distinct from the first portion; and combining at least the first portion of the intermediate session key contained within the preceding key distribution broadcast and the second portion of the intermediate session key contained within the subsequent key distribution broadcast to obtain the intermediate session key.

Systems and methods for non-interactive session key distribution with revocation

A print management system includes a policy that determines a protection level for a document to be printed. The document is printed using forgery detection and deterrence technologies, such as fragile and robust watermarks, glyphs, and digital signatures, that are appropriate to the level of protection determined by the policy. A plurality of printers are managed by a print management system. Each printer can provide a range of protection technologies. The policy determines the protection technologies for the document to be printed and the print management system routes the print job to a printer that can apply the appropriate protections and sets the appropriate parameters in the printer. Copy evidence that can verify that a document is a forgery and/or tracing information that identifies the custodian(s) of the document and restrictions on copying of the document and use of the information in the document are included in the watermark that is printed with the document information. A document can be verified as an original or a forgery by inspecting the copy evidence and/or tracing information in the watermark.

Systems and methods for policy based printing

A system, method and article of manufacture are provided for affording a cryptographic service utilizing a server on a network. Initially, a client is identified utilizing the network. A first key is established, and a tunnel is generated on the network. Thereafter, information is received at the server from the client utilizing the tunnel. Such information is encrypted by the client using the first key. At the server, cryptographic work is performed using the first key.

System, method and article of manufacture for providing cryptographic services utilizing a network

A method for enabling privacy and trust in electronic communities is disclosed. A major impediment to using recommendation systems and collective knowledge for electronic commerce is the reluctance of individuals to reveal preferences in order to find groups of people that share them. An equally important barrier to fluid electronic commerce is the lack of agreed upon trusted third parties. We propose new non-third party mechanisms to overcome these barriers. Our solutions facilitate finding shared preferences, discovering communities with shared values, removing disincentives posed by liabilities, and negotiating on behalf of a group. We adapt known techniques from the cryptographic literature to enable these new capabilities.

Method for enabling privacy and trust in electronic communities

A system, method, and article of manufacture are provided for pricing a cryptographic service on a network utilizing one or more cryptoservers. A request for a cryptographic service is received from a user utilizing a network. The request is received by a cryptographic service provider. A contract is generated based on a variable pricing scheme in response to the request. The contract is sent from the cryptographic service provider to the user utilizing the network. A method is also provided for auditing a security provision on a network utilizing a cryptoserver. A cryptographic key is obtained such as by obtaining it from a trusted source or generating the key. A plurality of users are allowed to request that a cryptoserver use the cryptographic key to sign a message in violation of a security provision. It is determined whether the cryptoserver signed the message in response to the request. An indication of failed security integrity is provided upon determining that the cryptographic server has signed the message.

System, method and article of manufacture for cryptoserver-based auction

A print management system includes a policy that determines a protection level for a document to be printed. The document is printed using forgery detection and deterrence technologies, such as fragile and robust watermarks, glyphs, and digital signatures, that are appropriate to the level of protection determined by the policy. A plurality of printers are managed by a print management system. Each printer can provide a range of protection technologies. The policy determines the protection technologies for the document to be printed. The print management system routes the print job to a printer that can apply the appropriate protections and sets the appropriate parameters in the printer. Copy evidence that can establish that a document is a forgery and/or tracing information that identifies the custodian of the document and restrictions on copying of the document and use of the information in the document are included in the watermark that is printed on the document. A document can be verified as an original or established as a forgery by inspecting the copy evidence and/or tracing information in the watermark.

Systems and methods for forgery detection and deterrence of printed documents

A system, method and article of manufacture are provided for secure operation of a network device. A digital certificate is assigned to a network user. A command for operation of a network device and the digital certificate are received from the network user. A cryptographic key stored in the network device is utilized to authenticate the digital certificate of the network user. Operation of the network device is enabled if the digital certificate of the network user is authenticated. According to another aspect of the present invention, a system, method and article of manufacture are provided for secure identification of a network device. A digital certificate is assigned to a network device. A command for operation of the network device is received from a network user. The digital certificate is sent to the network user. The network user utilizes a cryptographic key to authenticate the digital certificate of the network device. Operation of the network device is enabled if the digital certificate of the network device is authenticated. In another embodiment of the present invention, a system, method and article of manufacture are provided for secure management of a network device. Policy information and/or a computational protocol are associated with a command for the network device. The policy information and/or computational protocols are encrypted, sent to the network device, and decrypted. The network device utilizing the policy information and/or computational protocols processes the command.

System, method and article of manufacture for a cryptographic key infrastructure for networked devices

A system, method and article of manufacture are provided for certifying contracts utilizing a network. Initially, a first and second contract is received utilizing a network. Each contract includes a plurality of terms. It is then certified that the terms of the second contract are consistent with the terms of the first contract.

System, method and article of manufacture for contract term certification utilizing a network

A system, method and article of manufacture are provided for transition state-based cryptography in an application including at least one state having a state key associated with it. A request for access is sent to a server utilizing a network upon reaching a state in the application. The request includes a state key associated with the state. A reply is received from the server in response to the request. The reply includes an access key for providing the access if the state key is valid. According to another embodiment of the present invention, a method is provided for transition state-based cryptography in an application including at least one state having a state key associated with it. A request for access is received from a client to a server utilizing a network. The state key is verified at the server. A reply is sent from the server in response to the request. The reply includes an access key for providing the access if the state key is verified. In one aspect of the present invention, the request for access is for a subsequent state in the application.

System, method and article of manufacture for transition state-based cryptography

A symmetric key encryption system includes a printer or copier for performing decryption in two passes. During a first pass an encrypted image is decrypted to define a first partially decrypted image and during a second pass a complement of the encrypted image is decrypted to define a second partially decrypted image. The first partially decrypted image is formed when the encrypted image is rendered onto a first recording medium through a stencil. The stencil, which is a random arrangement of holes, is overlaid on the first recording medium to permit only selected portions of the encrypted image to be rendered on the recording medium. During the second pass, the complement of the encrypted image is rendered on a second recording medium through a complement of the stencil to yield the second partially decrypted image. Overlaying and aligning the first partially decrypted image and the second partially decrypted image finally decrypts the encrypted image.

Growing community of inventors

Palo Alto, CA, United States of America

Matthew K Franklin