Patents by Inventor Silvio Micali

Silvio Micali has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20030221101
    Abstract: We propose new systems for certificate revocation that are more economical and efficient than traditional ones. We also point out what we believe to be a structural problem in traditional public-key infrastructures, and various ways to solve it.
    Type: Application
    Filed: March 21, 2003
    Publication date: November 27, 2003
    Inventor: Silvio Micali
  • Patent number: 6487658
    Abstract: We propose new systems for certificate revocation that are more economical and efficient than traditional ones. We also point out what we believe to be a structural problem in traditional public-key infrastructures, and various ways to solve it.
    Type: Grant
    Filed: December 18, 1997
    Date of Patent: November 26, 2002
    Assignee: Corestreet Security, Ltd.
    Inventor: Silvio Micali
  • Publication number: 20020165824
    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.
    Type: Application
    Filed: March 20, 2002
    Publication date: November 7, 2002
    Inventor: Silvio Micali
  • Publication number: 20020107814
    Abstract: A method of managing certificates in a communication system having a certifying authority and a directory. Preferably, the method begins by having the certifying authority generate certificates by digitally signing a given piece of data. At a later point time, the certifying authority may produce a string that proves whether a particular certificate is currently valid without also proving the validity of at least some other certificates. The technique obviates use of certification revocation lists communicated between the certifying authority and the directory.
    Type: Application
    Filed: July 25, 2001
    Publication date: August 8, 2002
    Inventor: Silvio Micali
  • Publication number: 20020046337
    Abstract: A method and system for overcoming the problems associated with certificate revocation lists (CRL's), for example, in a public key infrastructure. The invention uses a tree-based scheme to replace the CRL.
    Type: Application
    Filed: September 6, 2001
    Publication date: April 18, 2002
    Inventor: Silvio Micali
  • Patent number: 6301659
    Abstract: A method and system for overcoming the problems associated with certificate revocation lists (CRL's), for example, in a public key infrastructure. The invention uses a tree-based scheme to replace the CRL.
    Type: Grant
    Filed: November 26, 1997
    Date of Patent: October 9, 2001
    Inventor: Silvio Micali
  • Patent number: 6292893
    Abstract: A certification revocation system uses a one-way function F to verify the validity of a certificate that includes a first value V. Included are means for receiving a second value V′ and means for iterating F on V′ and for comparing the result thereof to V. The function F is used to verify that a certificate having an issue date D and including a first value V is valid at a date belonging to a sequence of dates after D.
    Type: Grant
    Filed: January 14, 2000
    Date of Patent: September 18, 2001
    Inventor: Silvio Micali
  • Patent number: 6141750
    Abstract: An electronic communication in the presence of a trusted party enables an exchange of unpredictable values in which a second party receives a first value produced by a first party and unpredictable to the second party if and only if the first party receives a second value produced by the second party and unpredictable to the first party. The communication includes exchanging a first set of communications between the first and second parties without participation of the trusted party to attempt completion of the exchange of unpredictable values. If the exchange of unpredictable values is not completed using the first set of communications between the first and second parties, the trusted party takes action to complete the exchange. At least one party is authenticated to belong to a group of parties that exchanges unpredictable values. The group may be a group of subscribers. The at least one party may be authenticated by a digital signature. The digital signature may be produced by the trusted party.
    Type: Grant
    Filed: September 29, 1997
    Date of Patent: October 31, 2000
    Inventor: Silvio Micali
  • Patent number: 6137884
    Abstract: A number of electronic communications methods are described involving a first and a second party (i.e., sender and recipient), with assistance from at least a trusted party, enabling electronic transactions in which the first party has a message for the second party. The first party, the second party and the trusted party undertake an exchange of transmissions, such that if all transmissions reach their destinations the second party only receives the message if the first party receives at least one receipt. Preferably, the identity of the first party is temporarily withheld from the second party during the transaction. At least one receipt received to the first party enables the first party to prove the content of the message received by the second party.
    Type: Grant
    Filed: May 2, 1997
    Date of Patent: October 24, 2000
    Assignee: Bankers Trust Corporation
    Inventor: Silvio Micali
  • Patent number: 6134326
    Abstract: A communication method between a first and second party, in the presence of a trusted party, that enables a transaction in which the second party receives a first value produced by the first party and unpredictable to the second party if and only if the first party receives a second value produced by the second party and unpredictable to the first party. The method includes two basic steps: exchanging a first set of communications between the first and second parties without participation of the trusted party to attempt completion of the transaction, and if the transaction is not completed using the first set of communications between the first and second parties, having the trusted party take action to complete the transaction.
    Type: Grant
    Filed: April 2, 1997
    Date of Patent: October 17, 2000
    Assignee: Bankers Trust Corporation
    Inventor: Silvio Micali
  • Patent number: 6097811
    Abstract: A method and system for overcoming the problems associated with certificate revocation lists (CRL's), for example, in a public key infrastructure. The invention uses a tree-based scheme to replace the CRL.
    Type: Grant
    Filed: October 11, 1996
    Date of Patent: August 1, 2000
    Inventor: Silvio Micali
  • Patent number: 6026163
    Abstract: A distributed split-key cryptosystem and application in a public-key setting wherein each of a plurality of trustees independently selects his own secret-public key pair. The trustees combine their public encryption keys into a single public encryption key. Using this combined public key for an electronic auction and other secure transactions.
    Type: Grant
    Filed: December 12, 1996
    Date of Patent: February 15, 2000
    Inventor: Silvio Micali
  • Patent number: 5960083
    Abstract: A method of managing certificates in a communication system having a certifying authority and a directory. Preferably, the method begins by having the certifying authority generate certificates by digitally signing a given piece of data. At a later point time, the certifying authority may produce a string that proves whether a particular certificate is currently valid without also proving the validity of at least some other certificates. The technique obviates use of certification revocation lists communicated between the certifying authority and the directory.
    Type: Grant
    Filed: March 24, 1997
    Date of Patent: September 28, 1999
    Inventor: Silvio Micali
  • Patent number: 5812670
    Abstract: Encryption is a common tool to achieve privacy of communication in networks whose lines are not physically protected. In most communication networks, however, having a sender S send an encrypted message to a recipient R does not hide the very fact that S has sent a message to R, and this may in itself constitute valuable information that the parties would rather keep confidential. A transmission method is described that (1) keeps the identities of senders and receivers confidential, but (2) can trace senders and receivers under certain given circumstances.
    Type: Grant
    Filed: February 28, 1996
    Date of Patent: September 22, 1998
    Inventor: Silvio Micali
  • Patent number: 5793868
    Abstract: Authenticating information about revoked certificates includes generating data identifying the revoked certificates, generating information about the revoked certificates including the data without including the revocation date of every one of the revoked certificates, and having the authority authenticate the information. The data may be generated by performing a hash of at least a portion of each of the certificates. Generating information about the revoked certificates may include adding a date indicating when the information was authenticated and may exclude the revocation date of any one of the revoked certificates in the list.
    Type: Grant
    Filed: November 5, 1996
    Date of Patent: August 11, 1998
    Inventor: Silvio Micali
  • Patent number: 5790665
    Abstract: An information retrieval system in which data is retrieved anonymously by a user with the assistance of one or more trusted agents.
    Type: Grant
    Filed: January 17, 1997
    Date of Patent: August 4, 1998
    Inventor: Silvio Micali
  • Patent number: 5717759
    Abstract: A method for certifying public keys of a digital signature scheme in a communications system is provided. The secure communications system is one in which there are at least two levels of authorities. A user presents a piece of data to an intermediate level authority who, upon verifying the data, causes an issuing authority to issue a certificate that the piece of data posses a given property. Although the certificate is compacted by not having it contain a pubic key of the intermediate authority, nonetheless, information is stored in order to keep the intermediate authority accountable.
    Type: Grant
    Filed: January 31, 1997
    Date of Patent: February 10, 1998
    Inventor: Silvio Micali
  • Patent number: 5717757
    Abstract: An authority provides authenticated information about a plurality of certificate identifiers by generating a data string identifying all the plurality of certificate identifiers and by having the authority authenticate one or more of the data string alone, the data string together with date information, or the data string together with additional information. The date information may include the date of authentication. The additional information may include a date of issuance of at least one of the certificates. The additional information may include certificate information about at least some of the issued certificates. The certificate information may include one or more of: revocation information or validity information of at least some of the issued certificates.
    Type: Grant
    Filed: November 19, 1996
    Date of Patent: February 10, 1998
    Inventor: Silvio Micali
  • Patent number: RE35808
    Abstract: A method, using a public-key cryptosystem, for enabling a predetermined entity to monitor communications of users .?.suspected of unlawful activities while protecting the privacy of law-abiding users.!., wherein each user is assigned a pair of matching secret and public keys. According to the method, each user's secret key is broken into shares. Then, each user provides a plurality of "trustees" pieces of information. The pieces of information provided to each trustee enable that trustee to verify that such information includes a "share" of a secret key of some given public key. Each trustee can verify that the pieces of information provided include a share of the secret key without interaction with any other trustee or by sending messages to the user. Upon a predetermined request or condition, e.g., a court order authorizing the entity to monitor the communications of a user .?.suspected of unlawful activity.!., the trustees reveal to the entity the shares of the secret key of such user.
    Type: Grant
    Filed: September 12, 1995
    Date of Patent: May 26, 1998
    Assignee: Bankers Trust Company
    Inventor: Silvio Micali
  • Patent number: RE36918
    Abstract: A method, using a public-key cryptosystem, for enabling a predetermined entity to monitor communications of users .[.suspected of unlawful activities while protecting the privacy of law-abiding users.]., wherein each user is assigned a pair of matching secret and public keys. According to the method, each user's secret key is broken into shares. Then, each user provides a plurality of "trustees" pieces of information. The pieces of information provided to each trustee enable that trustee to verify that such information includes a "share" of a secret key of some given public key. Each trustee can verify that the pieces of information provided include a share of the secret key without interaction with any other trustee or by sending messages to the user. Upon a predetermined request or condition, e.g., a court order authorizing the entity to monitor the communications of a user .[.suspected of unlawful activity.]., the trustees reveal to the entity the shares of the secret key of such user.
    Type: Grant
    Filed: September 12, 1995
    Date of Patent: October 17, 2000
    Assignee: CertCo LLC
    Inventor: Silvio Micali