Abstract: A cost-effective system that provides for the efficient protection of transmitted non-public attribute information may be used, for example, to control access to a secure area. Encryption of the attribute information may be performed using symmetric encryption techniques, such as XOR and/or stream cipher encryption. A centralized database that stores and transmits the encrypted attribute information may generate the encryption/decryption key based on selected information bytes, for example, as taken from a card inserted into a handheld device used at the secure area. The selected information to generate the encryption key stream may be varied on a periodic basis by the centralized database. Information as to which selected bytes are to be used for a particular access authorization request may be transmitted to the handheld unit or may be input through action of a user of the handheld unit, for example by entry of a PIN code.

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a data about a credential includes having an entity issue authenticated data indicating that the credential has been revoked, causing the authenticated data to be stored in a first card of a first user, utilizing the first card for transferring the authenticated data to a first door,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.

Abstract: Controlling access includes providing a barrier to access that includes a controller that selectively allows access, at least one administration entity generating credentials/proofs, wherein no valid proofs are determinable given only the credentials and values for expired proofs, the controller receiving the credentials/proofs, the controller determining if access is presently authorized, and, if access is presently authorized, the controller allowing access. The credentials/proofs may be in one part or may be in separate parts. There may be a first administration entity that generates the credentials and other administration entities that generate proofs. The first administration entity may also generate proofs or the first administration entity may not generate proofs. The credentials may correspond to a digital certificate that includes a final value that is a result of applying a one way function to a first one of the proofs.

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: An entity controlling access of a plurality of users to at least one disconnected door includes mapping the plurality of users to a group, for each time interval d of a sequence of dates, having an authority produce a digital signature indicating that members of the group can access door during time interval d, causing at least one of the members of the group to receive the digital signature during time interval d for presentation to the door in order to pass therethrough, having the at least one member of the group present the digital signature to the door D, and having the door open after verifying that (i) the digital signature is a digital signature of the authority indicating that members of the group can access the door at time interval d, and (ii) that the current time is within time interval d.

Abstract: An administration entity controls access to an electronic device by generating credentials and a plurality of corresponding proofs, wherein no valid proofs are determinable given only the credentials and values for expired proofs. The electronic device receives the credentials and, if access is authorized at a particular time, the electronic device receives a proof corresponding to the particular time and confirms the proof using the credentials. A single administration entity may generate the credentials and generate the proofs and/or there may be a first administration entity that generates the credentials and other administration entities that generate proofs. The credentials may be a digital certificate that includes a final value that is a result of applying a one way function to a first one of the proofs.

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: Actuating a security system includes providing a first set of access codes to a wireless device and causing the wireless device to transmit the first set of access codes to a first controller that actuates the security system. The first set of access codes provided to the wireless device may expire. Actuating a security system may also include providing expiration dates for each of the first set of access codes provided to the wireless device. Actuating a security system may also include examining each of the expiration dates and, in response to a particular expiration date being prior to a current date, erasing from the wireless device a particular one of the first set of access codes that corresponds to the particular expiration date.

Abstract: Determining access includes determining if particular credentials/proofs indicate that access is allowed, determining if there is additional data associated with the credentials/proofs, wherein the additional data is separate from the credentials/proofs, and, if the particular credentials/proofs indicate that access is allowed and if there is additional data associated with the particular credentials/proofs, then deciding whether to deny access according to information provided by the additional data. The credentials/proofs may be in one part or in separate parts. There may be a first administration entity that generates the credentials and other administration entities that generate proofs. The first administration entity may also generate proofs or may not generate proofs. The credentials may correspond to a digital certificate that includes a final value that is a result of applying a one way function to a first one of the proofs.

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: 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: A cost-effective system that provides for the efficient protection of transmitted non-public attribute information may be used, for example, to control access to a secure area. Encryption of the attribute information may be performed using symmetric encryption techniques, such as XOR and/or stream cipher encryption. A centralized database that stores and transmits the encrypted attribute information may generate the encryption/decryption key based on selected information bytes, for example, as taken from a card inserted into a handheld device used at the secure area. The selected information to generate the encryption key stream may be varied on a periodic basis by the centralized database. Information as to which selected bytes are to be used for a particular access authorization request may be transmitted to the handheld unit or may be input through action of a user of the handheld unit, for example by entry of a PIN code.

Abstract: Actuating a security system includes providing a first set of access codes to a wireless device and causing the wireless device to transmit the first set of access codes to a first controller that actuates the security system. The first set of access codes provided to the wireless device may expire. Actuating a security system may also include providing expiration dates for each of the first set of access codes provided to the wireless device. Actuating a security system may also include examining each of the expiration dates and, in response to a particular expiration date being prior to a current date, erasing from the wireless device a particular one of the first set of access codes that corresponds to the particular expiration date.

Abstract: Actuating a security system includes providing a first set of access codes to a wireless device and causing the wireless device to transmit the first set of access codes to a first controller that actuates the security system. The first set of access codes provided to the wireless device may expire. Actuating a security system may also include providing expiration dates for each of the first set of access codes provided to the wireless device. Actuating a security system may also include examining each of the expiration dates and, in response to a particular expiration date being prior to a current date, erasing from the wireless device a particular one of the first set of access codes that corresponds to the particular expiration date.

Abstract: Determining whether to remotely authorize an action on behalf of a requester includes having the requester provide a privacy token, remotely obtaining data from the privacy token, and authorizing the action if the data from the privacy token verifies that the requester is authorized to take the action. The action may include issuing a credit card for the requester. The privacy token may be a smart card. The data may be digitally signed. Determining whether to remotely authorize an action on behalf of a requester may also include authorizing the action if the requester had previously indicated a desire not to require presentation of the privacy token. The action may be authorized only if the data from the privacy token verifies the identity of the requester.

Abstract: Actuating a security system includes providing a first set of access codes to a wireless device and causing the wireless device to transmit the first set of access codes to a first controller that actuates the security system. The first set of access codes provided to the wireless device may expire. Actuating a security system may also include providing expiration dates for each of the first set of access codes provided to the wireless device. Actuating a security system may also include examining each of the expiration dates and, in response to a particular expiration date being prior to a current date, erasing from the wireless device a particular one of the first set of access codes that corresponds to the particular expiration date.

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.

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 obtaining a plurality of signing key/verification key pairs, where each signing key provides a digital signature and a corresponding one of the verification keys verifies the digital signature and where digitally signing together a plurality of data elements using the signing keys is computationally more efficient than digitally signing each of the data elements individually, ascertaining digital certificate validity status for each certificate 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 certificates, and digitally signing together the artificially pre-computed messages using signing keys from the pairs. Ascertaining digital certificate validity status may include obtaining authenticated information about digital certificates.