Anonymous verifiable public key certificates
First Claim
1. A computer-readable medium, not consisting of a propagated signal, containing instructions which, when executed by one or more processors disposed in an electronic device, perform a method comprising the steps of:
- generating a set of blind certificates for a user in a population of users by a certificate authority;
utilizing a fixed-size PKI key set that is accessed by the certificate authority for generating the set of blind certificates on a per-user basis, each of the blind certificates arranged to limit the discloser of identifying information pertaining to the user, each of the blind certificates in the set being verifiable and providing anonymity for the user when used for authenticating the user, the fixed-size PKI key set being sized smaller than the user population so that identical public keys are simultaneously and commonly provided to each of a plurality of users in the population to cause the occurrence of keyset collisions to prevent tracing of the users;
randomly selecting a subset of key pairs from the fixed-size PKI key set on a per-user basis;
generating each blind certificate in the set of blind certificates by using respective public keys from the subset of key pairs, each blind certificate including a description including a listing and/or a limitation on a number of authorized devices to receive and render downloaded media content; and
providing the set of blind certificates and private keys from the subset of key pairs to the user.
2 Assignments
0 Petitions
Accused Products
Abstract
The anonymity of a user at a client computer may be preserved when authenticating with an on-line service or content provider through the use of an anonymous and verifiable (i.e., “blind”) certificate set that is created by a certificate authority from a fixed-size set of PKI key pairs. The certificate authority randomly selects a subset of PKI key pairs to generate the blind certificate set where each certificate in the set includes a respective public key from the PKI key pair subset. The certificate authority also sends the private keys from the PKI key pair subset to the user. During authentication, the client computer is configured to randomly select a subset of one or more certificates from the set to present to the provider. The provider will encrypt content using the public keys in the subset of certificates and the client will decrypt the content with the corresponding private keys.
31 Citations
21 Claims
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1. A computer-readable medium, not consisting of a propagated signal, containing instructions which, when executed by one or more processors disposed in an electronic device, perform a method comprising the steps of:
- generating a set of blind certificates for a user in a population of users by a certificate authority;
utilizing a fixed-size PKI key set that is accessed by the certificate authority for generating the set of blind certificates on a per-user basis, each of the blind certificates arranged to limit the discloser of identifying information pertaining to the user, each of the blind certificates in the set being verifiable and providing anonymity for the user when used for authenticating the user, the fixed-size PKI key set being sized smaller than the user population so that identical public keys are simultaneously and commonly provided to each of a plurality of users in the population to cause the occurrence of keyset collisions to prevent tracing of the users; randomly selecting a subset of key pairs from the fixed-size PKI key set on a per-user basis; generating each blind certificate in the set of blind certificates by using respective public keys from the subset of key pairs, each blind certificate including a description including a listing and/or a limitation on a number of authorized devices to receive and render downloaded media content; and providing the set of blind certificates and private keys from the subset of key pairs to the user. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
- generating a set of blind certificates for a user in a population of users by a certificate authority;
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9. A computer-readable medium, not consisting of a propagated signal, containing instructions which, when executed by one or more processors disposed in an electronic device, perform a method for using blind certificates among a population of users, the method comprising the steps of:
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generating a set of blind certificates for a user in the population of users by a certificate authority making a request to a certificate authority for blind certificates; receiving a set of blind certificates from the certificate authority, the blind certificates being generated on a per-user basis using public keys from a randomly selected subset of key pairs of a fixed-size PKI key set, each of the blind certificates arranged to limit the disclosure of identifying information pertaining to the user, and the blind certificates further being verifiable and providing anonymity for the user when used to authenticate the user, the fixed-size PKI key set being sized smaller than the user population so that identical public keys are simultaneously and commonly provided to each of a plurality of users in the population to cause the occurrence of keyset collisions to prevent tracing of the users; presenting more than one blind certificate from the set from the user to the authenticating party so that the authenticating party authenticates the user using the more than one blind certificates; and receiving content that is encrypted using public keys from each of the corresponding more than one presented blind certificates presented in said presenting step. - View Dependent Claims (10, 11, 12, 13, 14, 15)
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16. A computer-readable medium, not consisting of a propagated signal, containing instructions which, when executed by one or more processors disposed in an electronic device, perform a method comprising the steps of:
- authenticating a user in a population of users with blind certificates by an authenticating party,
receiving more than one blind certificate from a user seeking to be authenticated, each of the blind certificates arranged to limit the disclosure of identifying information pertaining to the user, the blind certificates being generated by a certificate authority on a per-user basis using public keys from a randomly selected subset of key pairs of a fixed-size PKI key set and being signed by the certificate authority with a signature, the fixed-size PKI key set being sized smaller than the user population so that identical public keys are simultaneously and commonly provided to each of a plurality of users in the population to cause the occurrence of keyset collisions to prevent tracing of the users; verifying the more than one blind certificates; authenticating the user using the verified more than one blind certificates; and binding content to more than one of the public keys so as to encrypt the content where the encrypted content is decrypted using corresponding multiple private keys from the subset of key pairs and consumed by the user. - View Dependent Claims (17, 18, 19, 20, 21)
- authenticating a user in a population of users with blind certificates by an authenticating party,
Specification