Abstract: Generating a uniquely authentic copy of information uses a physical device that consistently produces unpredictable outputs based on inputs and the microstructure of the device. The device is verified to satisfy a given property. It is substantially difficult to manufacture another device that satisfies the given property and that produces a particular output in response to a particular input. Generating the uniquely authentic copy of information includes causing the device to be provided with a specific input to produce a specific output, causing the generation of a digital signature of the response and the information, and causing at least the device and the digital signature to be made available. Generating the uniquely authentic copy of information may also include making available the information, the specific input, and/or the specific output. The information may be a value of a banknote. The digital signature may be produced on behalf of an issuer.

Abstract: Providing information about digital certificate validity includes ascertaining digital certificate validity status for each of a plurality of digital certificates in a set of digital certificates, generating a plurality of artificially pre-computed messages about the validity status of at least a subset of the set of digital certificate of the plurality of digital certificates, where at least one of the messages indicates validity status of more than one digital certificate and digitally signing the artificially pre-computed messages to provide OCSP format responses that respond to OCSP queries about specific digital certificates in the set of digital certificates, where at least one digital signature is used in connection with an OCSP format response for more than one digital certificate. Generating and digitally signing may occur prior to any OCSP queries that are answered by any of the OCSP format responses.

Abstract: Providing information about digital certificate validity includes ascertaining digital certificate validity status for each of a plurality of digital certificates in a set of digital certificates, generating a plurality of artificially pre-computed messages about the validity status of at least a subset of the set of digital certificate of the plurality of digital certificates, where at least one of the messages indicates validity status of more than one digital certificate and digitally signing the artificially pre-computed messages to provide OCSP format responses that respond to OCSP queries about specific digital certificates in the set of digital certificates, where at least one digital signature is used in connection with an OCSP format response for more than one digital certificate. Generating and digitally signing may occur prior to any OCSP queries that are answered by any of the OCSP format responses.

Abstract: Providing information about digital certificate validity includes ascertaining digital certificate validity status for each of a plurality of digital certificates in a set of digital certificates, generating a plurality of artificially pre-computed messages about the validity status of at least a subset of the set of digital certificate of the plurality of digital certificates, where at least one of the messages indicates validity status of more than one digital certificate and digitally signing the artificially pre-computed messages to provide OCSP format responses that respond to OCSP queries about specific digital certificates in the set of digital certificates, where at least one digital signature is used in connection with an OCSP format response for more than one digital certificate. Generating and digitally signing may occur prior to any OCSP queries that are answered by any of the OCSP format responses.

Abstract: Logging events associated with accessing an area includes recording an event associated with accessing the area to provide an event recording and authenticating at least the event recording to provide an authenticated recording. Recording an event may include recording a time of the event. Recording an event may include recording a type of event. The event may be an attempt to access the area. Recording an event may include recording credentials/proofs used in connection with the attempt to access the area. Recording an event may include recording a result of the attempt. Recording an event may include recording the existence of data other than the credentials/proofs indicating that access should be denied. Recording an event may include recording additional data related to the area. Authenticating the recording may include digitally signing the recording.

Abstract: A system and method are disclosed for controlling physical access through a digital certificate validation process that works with standard certificate formats and that enables a certifying authority (CA) to prove the validity status of each certificate C at any time interval (e.g., every day, hour, or minute) starting with C's issue date, D1. C's time granularity may be specified within the certificate itself, unless it is the same for all certificates. For example, all certificates may have a one-day granularity with each certificate expires 365 days after issuance. Given certain initial inputs provided by the CA, a one-way hash function is utilized to compute values of a specified byte size that are included on the digital certificate and to compute other values that are kept secret and used in the validation process.

Abstract: Logging events associated with accessing an area includes recording an event associated with accessing the area to provide an event recording and authenticating at least the event recording to provide an authenticated recording. Recording an event may include recording a time of the event. Recording an event may include recording a type of event. The event may be an attempt to access the area. Recording an event may include recording credentials/proofs used in connection with the attempt to access the area. Recording an event may include recording a result of the attempt. Recording an event may include recording the existence of data other than the credentials/proofs indicating that access should be denied. Recording an event may include recording additional data related to the area. Authenticating the recording may include digitally signing the recording.

Abstract: A system and method are disclosed for controlling physical access through a digital certificate validation process that works with standard certificate formats and that enables a certifying authority (CA) to prove the validity status of each certificate C at any time interval (e.g., every day, hour, or minute) starting with C's issue date, D1. C's time granularity may be specified within the certificate itself, unless it is the same for all certificates. For example, all certificates may have a one-day granularity with each certificate expires 365 days after issuance. Given certain initial inputs provided by the CA, a one-way hash function is utilized to compute values of a specified byte size that are included on the digital certificate and to compute other values that are kept secret and used in the validation process.

Abstract: Logging events associated with accessing an area includes recording an event associated with accessing the area to provide an event recording and authenticating at least the event recording to provide an authenticated recording. Recording an event may include recording a time of the event. Recording an event may include recording a type of event. The event may be an attempt to access the area. Recording an event may include recording credentials/proofs used in connection with the attempt to access the area. Recording an event may include recording a result of the attempt. Recording an event may include recording the existence of data other than the credentials/proofs indicating that access should be denied. Recording an event may include recording additional data related to the area. Authenticating the recording may include digitally signing the recording.

Abstract: Indicating data currentness includes, on any date of a sequence of dates, issuing a proof indicating the currentness status of the data during a particular time interval. The proof may be a digital signature. The time interval may be in the form of a current date and an amount of time. The proof may include a digital signature of the time interval. The proof may include a digital signature of the time interval and the data. The proof may include a digital signature of the time interval and a compact form of the data, such as a hash. Indicating data currentness may also include distributing the proofs to a plurality of unsecure units that respond to requests by users for the proofs. Indicating data currentness may also include gathering a plurality of separate pieces of data and providing a single proof for the separate pieces of data. The data may be electronic documents.

Abstract: Providing information about digital certificate validity includes ascertaining digital certificate validity status for each of a plurality of digital certificates in a set of digital certificates, generating a plurality of artificially pre-computed messages about the validity status of at least a subset of the set of digital certificate of the plurality of digital certificates, where at least one of the messages indicates validity status of more than one digital certificate and digitally signing the artificially pre-computed messages to provide OCSP format responses that respond to OCSP queries about specific digital certificates in the set of digital certificates, where at least one digital signature is used in connection with an OCSP format response for more than one digital certificate. Generating and digitally signing may occur prior to any OCSP queries that are answered by any of the OCSP format responses.

Abstract: A micropayment system and method is presented for a payor U to establish payment to payee M for a transaction T, which typically has a very low value TV. The micropayment scheme minimizes the bank's processing costs, while at the same time eliminating the need for users and merchants to interact in order to determine whether a given micropayment should be selected for payment. In one embodiment, the micropayment scheme includes time constraints, which require that an electronic check C for the transaction T be presented to a bank B for payment within a predetermined time/date interval. In another embodiment, the micropayment scheme includes a selective deposit protocol, which guarantees that a user is never charged in excess of what he actually spends, even within a probabilistic framework. In another embodiment, the micropayment scheme includes a deferred selection protocol, which provides the bank with control and flexibility over the payment selection process.

Abstract: Managing a digital certificate includes a landlord providing a digital certificate, a secure hardware device generating a series of n hash values, the secure hardware device providing an nth hash value to the landlord, wherein other hash values are not readily available to the landlord, the landlord placing the nth hash value in the certificate, the landlord digitally verifying the certificate containing the nth hash value to obtain a digitally signed certificate, a tenant obtaining the digitally signed certificate, the tenant obtaining the n hash values and the tenant managing the certificate by periodically issuing a previous hash value in the series of n hash values in response to the certificate being valid when the previous hash value is issued.

Abstract: Logging events associated with accessing an area includes recording an event associated with accessing the area to provide an event recording and authenticating at least the event recording to provide an authenticated recording. Recording an event may include recording a time of the event. Recording an event may include recording a type of event. The event may be an attempt to access the area. Recording an event may include recording credentials/proofs used in connection with the attempt to access the area. Recording an event may include recording a result of the attempt. Recording an event may include recording the existence of data other than the credentials/proofs indicating that access should be denied. Recording an event may include recording additional data related to the area. Authenticating the recording may include digitally signing the recording.

Abstract: Indicating data currentness includes, on any date of a sequence of dates, issuing a proof indicating the currentness status of the data during a particular time interval. The proof may be a digital signature. The time interval may be in the form of a current date and an amount of time. The proof may include a digital signature of the time interval. The proof may include a digital signature of the time interval and the data. The proof may include a digital signature of the time interval and a compact form of the data, such as a hash. Indicating data currentness may also include distributing the proofs to a plurality of unsecure units that respond to requests by users for the proofs. Indicating data currentness may also include gathering a plurality of separate pieces of data and providing a single proof for the separate pieces of data. The data may be electronic documents.

Abstract: A system and method are disclosed for controlling physical access through a digital certificate validation process that works with standard certificate formats and that enables a certifying authority (CA) to prove the validity status of each certificate C at any time interval (e.g., every day, hour, or minute) starting with C's issue date, D1. C's time granularity may be specified within the certificate itself, unless it is the same for all certificates. For example, all certificates may have a one-day granularity with each certificate expires 365 days after issuance. Given certain initial inputs provided by the CA, a one-way hash function is utilized to compute values of a specified byte size that are included on the digital certificate and to compute other values that are kept secret and used in the validation process.

Abstract: Logging events associated with accessing an area includes recording an event associated with accessing the area to provide an event recording and authenticating at least the event recording to provide an authenticated recording. Recording an event may include recording a time of the event. Recording an event may include recording a type of event. The event may be an attempt to access the area. Recording an event may include recording credentials/proofs used in connection with the attempt to access the area. Recording an event may include recording a result of the attempt. Recording an event may include recording the existence of data other than the credentials/proofs indicating that access should be denied. Recording an event may include recording additional data related to the area. Authenticating the recording may include digitally signing the recording.

Abstract: A system and method are disclosed for controlling physical access through a digital certificate validation process that works with standard certificate formats and that enables a certifying authority (CA) to prove the validity status of each certificate C at any time interval (e.g., every day, hour, or minute) starting with C's issue date, D1. C's time granularity may be specified within the certificate itself, unless it is the same for all certificates. For example, all certificates may have a one-day granularity with each certificate expires 365 days after issuance. Given certain initial inputs provided by the CA, a one-way hash function is utilized to compute values of a specified byte size that are included on the digital certificate and to compute other values that are kept secret and used in the validation process.

Abstract: Issuing and disseminating a data about a credential includes having an entity issue authenticated data indicating that the credential has been revoked, causing the authenticated data to be stored in a first card of a first user, utilizing the first card for transferring the authenticated data to a first door, having the first door store information about the authenticated data, and having the first door rely on information about the authenticated data to deny access to the credential. The authenticated data may be authenticated by a digital signature and the first door may verify the digital signature. The digital signature may be a public-key digital signature. The public key for the digital signature may be associated with the credential. The digital signature may be a private-key digital signature. The credential and the first card may both belong to the first user.

Abstract: Facilitating a transaction between a first party and a second party includes, prior to initiating the transaction, one of the parties obtaining an artificially pre-computed OCSP response about a specific digital certificate, where the artificially pre-computed OCSP response is generated by an entity other than the first party and the second party, one of the parties initiating the transaction, in connection with the transaction, the first party providing the specific digital certificate to the second party, and the second party verifying the specific digital certificate using the artificially pre-computed OCSP response. The second party may obtain the artificially pre-computed OCSP response prior to the transaction being initiated. The second party may cache the artificially pre-computed OCSP response for future transactions. The first party may obtain the artificially pre-computed OCSP response prior to the transaction being initiated.