Cryptosystem designers frequently assume that secrets will be manipulated in closed, reliable computing environments. Unfortunately, actual computers and microchips leak information about the operations they process. This paper examines specific methods for analyzing power consumption measurements to find secret keys from tamper resistant devices. We also discuss approaches for building cryptosystems that can operate securely in existing hardware that leaks information.

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Differential Power Analysis

A method and device are provided for controlling access to data. Portions of the data are protected and rules concerning access rights to the data are determined. Access to the protected portions of the data is prevented, other than in a non-useable form; and users are provided access to the data only in accordance with the rules as enforced by a mechanism protected by tamper detection. A method is also provided for distributing data for subsequent controlled use of those data. The method includes protecting portions of the data; preventing access to the protected portions of the data other than in a non-useable form; determining rules concerning access rights to the data; protecting the rules; and providing a package including: the protected portions of the data and the protected rules. A user is provided controlled access to the distributed data only in accordance with the rules as enforced by a mechanism protected by tamper protection. A device is provided for controlling access to data having protected data portions and rules concerning access rights to the data. The device includes means for storing the rules; and means for accessing the protected data portions only in accordance with the rules, whereby user access to the protected data portions is permitted only if the rules indicate that the user is allowed to access the portions of the data.

System for controlling access and distribution of digital property

Systeme unifie de communication a programmation regroupant les communications de l'art anterieur (telles que par exemple la television, la radio, l'impression transmise electroniquement, et les communications par ordinateur) ainsi que les nouveaux mass medias specifiques aux utilisateurs. Unified programming communication system involving communications of the prior art (such as eg television, radio, print transmitted electronically, and computer communications) and new mass media specific users. Dans le systeme unifie, des moyens (205) et procedes mettant en oeuvre des systemes d'ordinateurs ont la capacite de produire des informations specifiques a un utilisateur particulier, simultanement a chaque poste (26) d'une pluralite de postes d'abonnes (26). In the unified system, means (205) and methods employing computer systems have the ability to generate specific information to a particular user, simultaneously with each station (26) a plurality of subscriber stations ( 26).

Signal processing apparatus and methods.

The invention provides a method, system, and computer program product to control the access, copying, and/or transfer of a digital asset by mobile, wireless devices using a digital voucher. The digital voucher references a primary content that contains all of the expression for that particular asset and a secondary content that contains information that can be distilled out as a preview. The information in the primary content can be limited to a specified duration or a specific number of viewings. The author, owner, or possessor of the digital asset specifies the terms and conditions for distribution of the digital asset. The digital voucher authorizes the mobile, wireless device to access a specified primary or secondary content that may be located elsewhere in the network. The mobile, wireless device can download a copy of portions or all of the content depending on the terms specified in the voucher.

Digital rights management in a mobile communications environment

A system for remote data acquisition and centralized processing and storage is disclosed called the DataTreasury System (600). The DataTreasury System provided comprehensive support for the processing of documents and electronic data associated with different applications including sale, business, banking and general consumer transactions. The system retrieves transaction data such as credit card receipts checks in either electronic or paper form at one or more remote locations, encrypts the data, transmits the encrypted data to a central location, transforms the data to a usable form, performs identification verification using signature data and biometric data, generates informative reports from the data and transmits the informative reports to the remote location(s). The DataTreasury System (200, 400, 600) has many advantageous features which work together to provide high performance, security, reliability, fault tolerance and low cost. First, the network architecture facilitates secure communication between the remote location(s) and the central processing facility. A dynamic address assignment algorithm performs load balancing among the system's servers for faster performance and higher utilization. Finally, partitioning scheme improves the error correction process.

Remote image capture with centralized processing and storage

A communication security system for data transmissions between different domains of a multiple domain communication network where each domain includes a host system and its associated resources of programs and communication terminals. The host systems and communication terminals include data security devices each having a master key which permits a variety of cryptographic operations to be performed. When a host system in one domain wishes to communicate with a host system in another domain, a common session key is established at both host systems to permit cryptographic operations to be performed. This is accomplished by using a mutually agreed upon cross-domain key known by both host systems and does not require each host system to reveal its master key to the other host system. The cross domain key is enciphered under a key encrypting key designated as the sending cross domain key at the sending host system and under a different key encrypting key designated as the receiving cross domain key at the receiving host system. The sending host system creates an enciphered session key and together with the sending cross-domain key performs a transformation function to reencipher the session key under the sending cross domain key for transmission to the receiving host system. At the receiving host system, the receiving host system using the receiving cross-domain key and the received session key, performs a transformation function to reencipher the received session key fron encipherment under the sending cross domain key to encipherment under the receiving host system master key. With the common session key now available in usable form at both host systems, a communication session is established and cryptographic operations can proceed between the two host systems.

Cryptographic communication security for multiple domain networks

A file security system for data files created at a first host system in one domain and recovered at a second host system in another domain of a multiple domain network. Each of said host systems contain a data security device provided with multiple host keys capable of performing a variety of cryptographic operations. Creation and recovery of a secure data file is accomplished without revealing the keys of either of the host systems to the other of the host systems. When the data file is to be created at the first host system, the first host system data security device provides a file recovery key for subsequent recovery of the data file at the second host system and enciphers first host system plaintext under a primary file key, which is related to the file recovery key, to obtain first host system ciphertext as the data file. The file recovery key is used as header information for the data file or maintained as a private file recovery key. When the data file is to be recovered at the second host system, the file recovery key is provided at the second host system and the second host system data security device performs a cryptographic operation to transform the file recovery key into a form which is usable to decipher the data file. The second host system data security device then uses the transformed file recovery key to perform a cryptographic operation to obtain the first host system ciphertext in clear form at the second host system.

Cryptographic file security for multiple domain networks

A file security system for data files associated with a host data processing system. The host system includes a data security device which contains a secure host master key and is capable of performing a variety of cryptographic operations. At initialization time, the host system generates a series of file keys for the associated storage media and protects them by enciphering the file keys under a variant of the host master key. When a data file is to be created, a random number is generated and defined as an operational key enciphered under the file key of a designated storage media. The host data security device, using the enciphered file key of the designated storage media, transforms the enciphered operational key under control of the host master key into a form which permits the operational key to be used for enciphering host data. The operational key enciphered under the file key of the designated storage media, as header information, together with the host data enciphered under the operational key is written on the storage media as an enciphered data file. When the data file is recovered, the host data security device, using the enciphered file key of the designated storage media, transforms the enciphered operational key header information under control of the host master key into a form which permits the operational key to be used for deciphering the enciphered data file to obtain the file data in clear form.

Cryptographic file security for single domain networks

In a data communication network which includes terminals interconnected via a central switch, a process for verifying the identity of a terminal user who is provided with secret data associated with his identity. In carrying out the verification process, the secret data is first encrypted at the terminal under a transfer-in key for transmission to an associated data processing system. When it is determined that the terminal user maintains an account at the associated data processing system, a first translate operation is performed to translate the data from encryption under the transfer-in key to encryption under an authentication key, both of which keys are protected under other keys which are different from each other, thereby providing an authentication parameter which may be used to verify the identity of the terminal user. When it is determined that the terminal user does not maintain an account at the associated data processing system, a second translate operation is performed to translate the data from encryption under the transfer-in key to encryption under a transfer-out key for transmission to the next associated host system, the switch or a remote host system. At each such node, except the switch, a determination is made as to whether a verification process can be performed otherwise, the encrypted data is translated for transmission to the next or a remote node of the network for such verification.

Cryptographic application for interbank verification

A method and system are disclosed for the implementation of a weakened privacy channel. This is achieved through use of a weakened symmetric cryptographic algorithm called commercial data masking. The masked text is created from clear text at one system and may to transported electronically to another system where the masked text may be unmasked to produce the clear text. The reason to use the commercial data masking algorithm for data privacy is that it is exportable to organizations to which products which contain the Data Encryption Algorithm when used for data privacy are not exportable. In addition, a method and system is disclosed by which the key when used for commercial data masking may be transformed into a key that may be used with the Data Encryption Algorithm.

Robert Carl Elander

Papers

Cryptographic communication security for multiple domain networks

Cryptographic file security for multiple domain networks

Cryptographic file security for single domain networks

Cryptographic application for interbank verification

Commercial Data Masking