Optionally moderated transaction systems
    1.
    发明授权
    Optionally moderated transaction systems 失效
    可选的主持式交易系统

    公开(公告)号:US5276736A

    公开(公告)日:1994-01-04

    申请号:US912193

    申请日:1992-07-13

    申请人: David Chaum

    发明人: David Chaum

    摘要: A tamper-resistant part is disclosed that can conduct transactions with an external system through a moderating user-controlled computer or that can on other occasions be brought into direct connection with the external system. In the moderated configuration, the moderating computer is able to ensure that certain transactions with the external system are unlinkable to each other. In the unmoderated configuration the tamper-resistant part can also ensure the unlinkability of certain transactions. Also testing configurations are disclosed that allow improper functioning of the tamper-resistant part, such as that which could link transactions, to be detected by user-controlled equipment. Another testing configuration can detect improper functioning of an external system that could, for instance, obtain linking information from a tamper-resistant part.

    摘要翻译: 公开了一种防篡改部件,其可以通过调节用户控制的计算机与外部系统进行交易,或者在其他情况下可以与外部系统直接连接。 在主持配置中,调节计算机能够确保与外部系统的某些事务彼此不可链接。 在未设计的配置中,防篡改部分还可以确保某些交易的不可连接性。 还公开了允许由用户控制的设备检测到的防篡改部分(例如可能链接事务的那些)的不正常功能的测试配置。 另一个测试配置可以检测外部系统的不正常功能,例如,可以从防篡改部分获取链接信息。

    CRYPTOGRAPHIC PHYSICAL RANDOM OBJECT

    公开(公告)号:US20220027912A1

    公开(公告)日:2022-01-27

    申请号:US17381504

    申请日:2021-07-21

    申请人: David CHAUM

    发明人: David CHAUM

    摘要: A value transfer system with physical tokens including indicia hiding means and indica substantially hidden by the hiding means and the hiding being substantially removable is improved by providing a plurality of regions with substantially removable hiding means, with the hiding means substantially hiding respective indicia. The indicia information is substantially unpredictable. As part of the system, a first party provides digitally to at least a second party first transaction information at least including a provenience signature ensemble, with the signature ensemble including at least indication of the regions with hiding removed.

    Optionally moderated transaction systems
    3.
    发明授权
    Optionally moderated transaction systems 失效
    可选择的现代交易系统

    公开(公告)号:US5131039A

    公开(公告)日:1992-07-14

    申请号:US609519

    申请日:1990-11-05

    申请人: David Chaum

    发明人: David Chaum

    IPC分类号: G07F7/10 H04L9/32

    摘要: A tamper-resistant part is disclosed that can conduct transactions with an external system through a moderating user-controlled computer or that can on other occasions be brought into direct connection with the external system. In the moderated configuration, the moderating computer is able to ensure that certain transactions with the external system are unlinkable to each other. In the unmoderated configuration, the tamper-resistant part can also ensure the unlinkability of certain transactions. Also testing configurations are disclosed that allow improper functioning of the tamper-resistant part, such as that which could link transactions, to be detected by user-controlled equipment. Another testing configuration can detect improper functioning of an external system that could, for instance, obtain linking information from a tamper-resistant part.

    Undeniable signature systems
    4.
    发明授权
    Undeniable signature systems 失效
    不可否认的签名系统

    公开(公告)号:US4947430A

    公开(公告)日:1990-08-07

    申请号:US123703

    申请日:1987-11-23

    申请人: David Chaum

    发明人: David Chaum

    IPC分类号: G07F7/10 G09C1/00 H04L9/32

    摘要: Cryptographic methods and apparatus for forming, checking, blinding, and unblinding of undeniable signatures are disclosed. The validity of such signatures is based on public keys and they are formed by a signing party with access to a corresponding private key, much as with public key digital signatures. A difference is that whereas public key digital signatures can be checked by anyone using the corresponding public key, the validity of undeniable signatures is in general checked by a protocol conducted between a checking party and the signing party. During such a protocol, the signing party may improperly try to deny the validity of a valid signature, but the checking party will be able to detect this with substantially high probability. In case the signing party is not improperly performing the protocol, the checking party is further able to determine with high probability whether or not the signature validly corresponds to the intended message and public key. Blinding can be used while obtaining undeniable signatures, while providing them to other parties, and while checking their validity.

    Cryptographic identification, financial transaction, and credential
device
    6.
    发明授权
    Cryptographic identification, financial transaction, and credential device 失效
    密码识别,金融交易和凭证设备

    公开(公告)号:US4529870A

    公开(公告)日:1985-07-16

    申请号:US392271

    申请日:1982-06-25

    申请人: David Chaum

    发明人: David Chaum

    摘要: The invention provides a cryptographic apparatus which may be "personalized" to its owner. The apparatus may be utilized by its owner to identify himself to an external computer system, to perform various financial transactions with an external system, and to provide various kinds of credentials to an external system. The apparatus, in one embodiment, is separable into a cryptographic device, packaged in a tamper resistant housing, and a personal terminal device. The cryptographic device includes interface circuitry to permit information exchange with the external system, a memory device for storage of data necessary to allow identification of the owner, and control logic for controlling the exchange of data with the external system to identify the owner. Certain data which must be utilized to perform the identification information exchange is stored in the memory device in encrypted form. The decryption of this data requires the entry of a secret ID, known to the owner.The personal terminal device includes a data entry capability to allow the owner to enter his secret ID. Certain embodiments of the personal terminal device include data display capability to provide transaction information to the owner. Other embodiments include memory devices and a processor to allow storage and manipulation of relatively unsecured data of the owner.

    摘要翻译: 本发明提供了可以对其所有者“个性化”的密码设备。 该装置可以由其所有者利用来向外部计算机系统识别自身,与外部系统执行各种金融交易,并向外部系统提供各种证书。 在一个实施例中,该装置可分离成密封装置,封装在防篡改外壳和个人终端装置中。 加密设备包括允许与外部系统进行信息交换的接口电路,用于存储允许识别所有者所需的数据的存储设备,以及用于控制与外部系统的数据交换以识别所有者的控制逻辑。 必须用于执行识别信息交换的某些数据以加密形式存储在存储装置中。 该数据的解密需要输入所有者知道的秘密ID。 个人终端设备包括允许所有者输入他的秘密ID的数据输入能力。 个人终端设备的某些实施例包括向业主提供交易信息的数据显示能力。 其他实施例包括存储器件和处理器,以允许存储和操纵所有者的相对不安全的数据。

    COMPUTATION MIXING
    7.
    发明申请

    公开(公告)号:US20220076253A1

    公开(公告)日:2022-03-10

    申请号:US17398255

    申请日:2021-08-10

    申请人: David CHAUM

    发明人: David CHAUM

    IPC分类号: G06Q20/38 G06Q20/36 H04L9/32

    摘要: A cryptographic protocol is provided that allows principals to securely realize a wide range of financial products simply via the protocol conducted between their respective phone apps. No other entities need play a role and no fees need be paid. A commitment fee is required to prevent the counterparty being spoofed and the system being discredited. If a party reneges during a transaction, that party is refunded their value and at least a share of a penalty levied on the reneging party.

    Returned-value blind signature systems
    8.
    发明授权
    Returned-value blind signature systems 失效
    返回值盲签名系统

    公开(公告)号:US4949380A

    公开(公告)日:1990-08-14

    申请号:US260053

    申请日:1988-10-20

    申请人: David Chaum

    发明人: David Chaum

    摘要: A payer party obtains from a signer party by a blind signature system a first public key digital signature having a first value in a withdrawal transaction; the payer reduces the value of the first signature obtained from the first value to a second value and provides this reduced-value form of the signature to the signer in a payment transaction; the signer returns a second digital signature to the payer by a blind signature system in online consummation of the payment transaction; the paper derives from the first and the second signature a third signature having a value increased corresponding to the magnitude of the difference between the first and the second values. Furthermore, the following additional features are provided: payments are unlinkable to withdrawals; a shop between the payer and signer can be kept from obtaining more value than desired by the payer; the first value need not be revealed to the signer or intermediary in the payment transaction; the returned difference can be accumulated across multiple payment transactions; and the returned difference can be divided between a plurality of payment transactions.

    摘要翻译: 付款方通过盲签名系统从登录方获得在提款交易中具有第一值的第一公钥数字签名; 付款人将从第一值获得的第一签名的价值降低到第二值,并在支付交易中向签署者提供该签名的减值形式; 签名者在网上完成支付交易时由盲签名系统向付款人返回第二数字签名; 该纸从第一和第二签名得出具有对应于第一和第二值之间的差的大小增加的值的第三签名。 此外,还提供了以下附加功能:付款与取款无关; 付款人和签字人之间的商店可以免于获得比付款人所期望的更多的价值; 第一个价值不需要在支付交易中向签字人或中间人透露; 返回的差额可以跨多个付款交易累积; 并且返回的差异可以在多个支付交易之间分配。

    Precomputed and transactional mixing

    公开(公告)号:US11184338B2

    公开(公告)日:2021-11-23

    申请号:US16439863

    申请日:2019-06-13

    申请人: David Chaum

    发明人: David Chaum

    摘要: 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—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.

    Unpredictable blind signature systems
    10.
    发明授权
    Unpredictable blind signature systems 失效
    不可预测的盲签名系统

    公开(公告)号:US4991210A

    公开(公告)日:1991-02-05

    申请号:US347303

    申请日:1989-05-04

    申请人: David Chaum

    发明人: David Chaum

    IPC分类号: G07F7/10 H04L9/32

    摘要: Blind signature systems secure against chosen message attack are disclosed. Multiple candidate original messages can be accommodated. Each of plural candidates in the final signature can be marked by the party issuing the signature in a way that is unmodifiable by the party receiving the signatures. The exponents on the candidates in the final signature need not be predictable by either party. In some embodiments, these exponents are not at all or are only partly determined by the candidates in the signature shown. Single candidate signatures are also accommodated.

    摘要翻译: 披露了针对所选消息攻击的盲签名系统。 可以容纳多个候选原始消息。 最终签名中的多个候选人中的每一个可以被发送签名的方以被接收到签名的一方不可修改的方式标记。 最终签名中候选人的指数不能由任何一方预测。 在一些实施例中,这些指数根本不是或仅部分地由所示签名中的候选者确定。 单一的候选签名也被容纳。