Patents by Inventor Claus Peter Schnorr

Claus Peter Schnorr 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).

  • Patent number: 7013295
    Abstract: Purchase of information items from a merchant over the Internet or other network is implemented so as to ensure that the merchant is unable to identify the particular information item(s) purchased by a user. The user when considering purchase of a given information item is permitted to access a corresponding signed ciphertext of that item. The signed ciphertext in an illustrative embodiment includes a first ciphertext portion in the form of a symmetric key encrypted using a public key associated with the merchant, a second ciphertext portion corresponding to the information item encrypted using the symmetric key, an unencrypted description of the information item, and a tag corresponding to a signature. The user requests purchase of the information item by sending a blinded version of the first ciphertext portion to a payment server along with an appropriate payment. The payment server decrypts the blinded version of the first ciphertext portion and returns the resulting symmetric key to the user.
    Type: Grant
    Filed: December 1, 2000
    Date of Patent: March 14, 2006
    Assignee: Lucent Technologies Inc.
    Inventors: Bjorn Markus Jakobsson, Claus Peter Schnorr
  • Patent number: 6931126
    Abstract: A fast encryption method particularly useful for long message lengths is provided. A message m is encrypted using a transmitter secret key z to form a quantity E. A transmitter processor prepares a quadruplet (anew, bnew,snew, E) where: anew=z*ycmodulo p; bnew=gcmodulo p; snew=signaturec(anew,bnew,E). As in previous embodiments y=gxmodulo p is the public key and x is the receiver secret key. The parameters g, x, and p according to methods known to a person skilled in the art and the parameter g is a generator of the group Gp. The parameter c is a random number. The transmitter processor sends the quadruplet (anew, bnew,snew, E) to a receiver processor. The receiver processor verifies the signature on snew using methods known in the art. The receiver processor then decrypts anew and bnew using the receiver secret key x to get the transmitter secret key z, i.e. in the following manner z=anew/bnewx. The receiver processor uses the transmitter secret key z to decrypt E to get the message M.
    Type: Grant
    Filed: January 19, 2000
    Date of Patent: August 16, 2005
    Assignee: Lucent Technologies Inc.
    Inventors: Bjorn Markus Jakobsson, Claus Peter Schnorr
  • Publication number: 20020069181
    Abstract: Purchase of information items from a merchant over the Internet or other network is implemented so as to ensure that the merchant is unable to identify the particular information item(s) purchased by a user. The user when considering purchase of a given information item is permitted to access a corresponding signed ciphertext of that item. The signed ciphertext in an illustrative embodiment includes a first ciphertext portion in the form of a symmetric key encrypted using a public key associated with the merchant, a second ciphertext portion corresponding to the information item encrypted using the symmetric key, an unencrypted description of the information item, and a tag corresponding to a signature. The user requests purchase of the information item by sending a blinded version of the first ciphertext portion to a payment server along with an appropriate payment. The payment server decrypts the blinded version of the first ciphertext portion and returns the resulting symmetric key to the user.
    Type: Application
    Filed: December 1, 2000
    Publication date: June 6, 2002
    Inventors: Bjorn Markus Jakobsson, Claus Peter Schnorr