Other

Digicash Incorporated

Infospace, Inc.

Amtech Corporation

Digital Community LLC

David L Chaum

Niels Thomas Ferguson

Jelte Van Der Hoek

Peter L Hendrick

Erik W Voskuil

Berry Schoenmakers

A method allows a random sample of a large population of voters to cast votes and for both the unpredictability/un-manipulability of the sample selection and the integrity of the tally to be verified by any interested parties using public information. The problem of vote selling is addressed. Also, a variant allows voters to remain substantially anonymous.

Random sample elections

Precomputed and transactional mixing is believed to allow portable devices, such as smart phones, to send and receive messages, with little extra bandwidth or battery usage, while achieving anonymity for senders and recipients among all messages sent globally in batches defined by short time intervals. To learn anything about which inputs correspond with which outputs of such a batch of messages, the entire cascade of mix devices, each preferably operating independently in a different country, would it is believed have to be compromised. None of the real-time computation, neither by the mixes nor smartphones, uses full public-key operations&#x2014;resulting it is believed in orders of magnitude performance improvement over previously-known systems. Aspects include untraceable return addresses, group chat, feed-following and large payloads. Transaction protocols include a variety of payments use cases. Limited anonymity and credential mechanism are based on a new approach to user identification disclosed, in which each user provides a small amount of different identifying information to each mix node, so that comparatively little is revealed to each node individually.

Precomputed and transactional mixing

Disclosed are systems and methods for providing video content while inhibiting the copying of that content for later viewing. Video images may be made difficult to copy for presentation at later times by the omission or addition of content developed in relation to the particular initial viewing. For instance, video information may be customized by omitting information that is not likely to be substantially perceived by the initial viewer but that is substantially likely to be perceived as missing by at least some other viewers. As another example, video information may be customized for a particular viewing instance so that it contains modified, selected or injected information that is likely to be perceived as non-disruptive or unnoticeable by the original viewer but that would be perceived as substantially noticeable and/or disruptive by some other viewers, including when parts of more than one such video information are combined in an effort to remove customization related to their respective original viewings. Various means and methods for accomplishing the forgoing in a variety of settings are disclosed including also for providing privacy related to what is viewed. In some examples higher-resolution images are provided for the region near the viewer's point-of-regard and lower resolution images are provided elsewhere, which also has the effect of reducing the bandwidth required. For interactive content rendered from digital models, a model for a central foveal region may be provide greater detail and have greater computational requirements than a model for a peripheral view, providing both economy/performance in rendering and protection against copying.

Video copy prevention systems with interaction and compression

A paper-ballot voting system is disclosed in which voters can retain symbols printed adjacent to the particular candidates or ballot question positions that they mark. Including ballot serial numbers on the forms allows voters to check online the symbols recorded for their ballots while maintaining ballot secrecy. In case of dispute, a physical resolution procedure lets voters establish whether the recorded symbols are correct with respect to the actual physical ballots. Some examples allow forms to be obtained online and voted by physical or facsimile delivery. Voters who cannot read ballots or cannot mark ballots can nevertheless vote while maintaining ballot secrecy. The overall integrity of the outcome is provided transparently.

Scan-integrity election systems

An improved paper ballot voting system allows voters to verify that their ballots are correctly counted and provide substantiating evidence if they are not. Codes are revealed to voters by the act of marking the ballot during voting and voters can check that these codes are posted. If these codes are not posted as marked, voters can make the codes they obtained public. These codes made public by voters can be compared against codes that were cryptographically committed to in advance of the election. If the codes from voters do in fact match codes committed to, evidence of incorrectness of the vote tallying is provided.

Hidden-code voting and marking systems

Disclosed are voting systems based on paper ballots that provide integrity of the election outcome through the novel use of encrypted votes and other techniques. In some example embodiments, holes through layers allow voters to see and mark symbols on lower layers, carbonless coatings allow voters to obtain substantially identical marks on facing surfaces, self-adhesive stickers are removed from one position and placed by voters hiding vote-revealing indicia on a second position, and scratch-off layers bearing vote-revealing indicia are destroyed while being removed to expose coded information. Simplified cryptography for realizing these systems is also presented. Related systems allow those with various disabilities to develop and check voted ballot forms that are substantially indistinguishable from those voted by other voters. Inclusion of write-in votes is provided for. Also provided are inclusion of provisional ballots and spoilt ballots and integration with registration sign-in.

Ballot integrity systems

An election system provides, in one example, each voter with multiple physical 'layers' that the voter is able to choose between. The voter takes part of the layers as a kind of receipt and the other layers are retained and/or destroyed by the system. The actual vote is not readily revealed by the layers taken by the voter, thus protecting against improper influence. In the voting booth, when all the layers are combined, however, the voter is readily able to verify the vote. Moreover, posted images of the layers not taken by the voter can be used to compute the election results in a way that is verifiable by interested parties. The results cannot be changed without substantial probability of detection and privacy of votes can be maintained unless a number of parties are compromised or collude.

Secret-ballot systems with voter-verifiable integrity

Disclosed is a multi-purpose transaction card system comprising an issuer, one or more cards, one or more terminals, and optionally one or more acquires, communicating using a variety of cryptographic confidentiality and authentication methods. Cards authenticate messages using public key based cryptographic without themselves performing the extensive computations usually associated with such cryptography. Integrity of complex transaction sequences and plural card storage updates are maintained even under intentionally generated interruptions and/or modifications of data transmitted between card and terminal. Cards do not reveal any information to the terminal which is not directly necessary for the transaction or any information to which the terminal should not have access, though externally measurable aspects of its behavior. Transaction types supported include those suitable for off-line credit cards, in which the &ldquo;open to buy&rdquo; is maintained on the card.

Multi-purpose transaction card system

Disclosed is a multi-purpose transaction card system comprising an issuer, one or more cards, one or more terminals, and optionally one or more acquires, communicating using a variety of cryptographic confidentiality and authentication methods. Cards authenticate messages using public key based cryptographic without themselves performing the extensive computations usually associated with such cryptography. Integrity of complex transaction sequences and plural card storage updates are maintained, even under intentionally generated interruptions and/or modifications of data transmitted between card and terminal. Cards do not reveal any information to the terminal which is not directly necessary for the transaction or any information to which the terminal should not have access, though externally measurable aspects of its behavior. Transaction types supported include those suitable for off-line credit cards, in which the &ldquo;open to buy&rdquo; is maintained on the card.

An electronic lock that can be pre-programmed or trained in the field to recognize ordinary flat metal keys by sensing their shape and comparing to a database is disclosed. The lock can be contained in standard configurations for door locks, communicates with external systems, provides control logic for querying and amending its database of allowed keys and rules, provides controlled access to logs of selected data, allows convenient but protected access to replacement batteries, can have all its electronics in the rotatable plug, can communicate and obtain power from devices in the adjacent door jam, can recognize special series key-blanks, can receive coded information entered using an unknown key that makes it useable, can be operated without a key to gain access with a code, can resist manipulation of the latching mechanism can unlatch with very low power requirements, and provides for integration of almost all mechanism in silicon.

Electronic lock that can learn to recognize any ordinary key

An information storage system includes one or more information update terminals, a mapper, one or more partial-databases, and one or more query terminals, exchanging messages over a set of communication channels. An identifier-mapping mechanism provides (to an update terminal) a method for delegating control over retrieval of the data stored at the partial-databases to one or more mappers, typically operated by one or more trusted third parties. Update terminals supply information, that is stored in fragmented form by the partial-databases. Data-fragment identifiers and pseudonyms are introduced, preventing unauthorized de-fragmentation of information--thus providing compliance to privacy legislation--while at the same time allowing query terminals to retrieve (part of) the stored data or learn properties of the stored data. The mapper is necessarily involved in both operations, allowing data access policies to be enforced and potential abuse of stored information to be reduced. Introduction of multiple mappers acts to distribute information retrieval control among multiple trusted third parties. Introducing so-called `groupers` increases the efficiency of data retrieval for a common set of queries and further reduces potential abuse of information.

Partitioned information storage systems with controlled retrieval

Cryptographic methods and apparatus for payment and related transaction systems are disclosed that allow some kinds of tracing under some conditions and make substantially infeasible other kinds of tracing under other conditions. Examples include: allowing tracing if and only if agreed sets of trustees cooperate; tracing from a payment to the payer by cooperation of a set of trustees; tracing from a payment to the payer without revealing to trustees which payer is being traced or which payment; identifying all payments by a payer provided appropriate trustees cooperate; and identifying all payments by a payer under investigation without trustees learning which payer and/or which payments; Other examples include: limiting resolution to groups of payers in tracing for statistical purposes; allowing limited different markings of payment instruments while preventing payers from learning which marking they receive; providing for recovery of lost money without compromise of unrelated transactions; allowing participants the ability to retain, not forward, and even destroy some tracing information without financial harm; providing the option of artificial increase in the computational cost of at least some tracing; and providing the option of blurry linking of payments to payers.

Growing community of inventors

Sherman Oaks, CA, United States of America

David L Chaum