Abstract: A user friendly two factor authentication method and system for a user is disclosed. In an embodiment the system includes a user device, an authentication server, a network interconnecting the user device and authentication server and software on the user device and authentication server that cooperates to first register the user by storing first key share K1 of an authentication key K on the user device and storing a second key share K2 of K blinded by a user chosen password on the authentication server, and then authenticate the user by implementing a protocol where the user's knowledge of the password and the possession of the user device is used to derive the key K for authentication. Thus, the two factors are checked in one integrated protocol, thereby requiring no additional work or change in user behavior.

Abstract: The present invention describes a method for authenticating a user of a mobile device by a verification authority, by making use of at least a personal identification number (PIN) and at least one cryptographic key, such that the PIN and the cryptographic key is known only to the user and the verification authority. The cryptographic key has at least one session key. Firstly, the user encodes the PIN by using at least one session key and then transfers the encoded PIN to a predefined address of the verification authority via the mobile device. Next, the verification authority decodes the PIN by using the cryptographic key authenticates the user if the decoded PIN matches a PIN stored corresponding to the user.

Abstract: A method and system for cryptographically indexing, searching for, and retrieving documents is provided. In some embodiments, an encryption system is provided that generates a document index that allows users to retrieve documents by performing encrypted queries for keywords associated with the documents. In some embodiments, each keyword maps to the same number of encrypted document identifiers. In some embodiments, an extractor graph is employed to map an indication of each keyword to a number of buckets storing encrypted document identifiers. In some embodiments, an order-preserving encryption system is provided. The encryption system uses an ordered index that maps encrypted instances of ordered attribute values to documents that are associated with those values. The ordered index enables queries containing query operators that rely on order, such as less than (“<”) or greater than (“>”), to be successfully performed on encrypted attribute values.

Abstract: The present invention describes a method for authenticating a user of a mobile device by a verification authority, by making use of at least a personal identification number (PIN) and at least one cryptographic key, such that the PIN and the cryptographic key is known only to the user and the verification authority. The cryptographic key has at least one session key. Firstly, the user encodes the PIN by using at least one session key and then transfers the encoded PIN to a predefined address of the verification authority via the mobile device. Next, the verification authority decodes the PIN by using the cryptographic key authenticates the user if the decoded PIN matches a PIN stored corresponding to the user.

Abstract: Users make online purchases using a virtual currency. A series of secret encryption keys is generated, where each key in the series is associated with a different epoch. A token tracking table is initialized. Whenever real currency is received from a user wanting to purchase tokens, a semantically secure encryption method is used in conjunction with the secret encryption key in the series that is associated with the current epoch to generate a set of encrypted tokens which includes one or more encrypted paid tokens. The set of encrypted tokens is sent to the user wanting to purchase tokens, and each encrypted paid token in the set is entered into the token tracking table, where the entry for each encrypted paid token includes information specifying that the token has not yet been spent and has not yet been encashed.

Abstract: A method and system for cryptographically indexing, searching for, and retrieving documents is provided. In some embodiments, an encryption system is provided that generates a document index that allows users to retrieve documents by performing encrypted queries for keywords associated with the documents. In some embodiments, each keyword maps to the same number of encrypted document identifiers. In some embodiments, an extractor graph is employed to map an indication of each keyword to a number of buckets storing encrypted document identifiers. In some embodiments, an order-preserving encryption system is provided. The encryption system uses an ordered index that maps encrypted instances of ordered attribute values to documents that are associated with those values. The ordered index enables queries containing query operators that rely on order, such as less than (“<”) or greater than (“>”), to be successfully performed on encrypted attribute values.