Abstract: On a recording medium, first information obtained by enciphering data with the first key and second information obtained by enciphering the first key with each of the predetermined second keys are recorded. A deciphering method is characterized by comprising the steps of inputting the first and second information, deciphering the first key using at least one of the second keys, determining by a specific method that the obtained first key is correct, and then deciphering the data using the first key to obtain the data.

Abstract: An integrated circuit card includes a memory storing service data relating to at least one service. At least part of the memory comprises data in file structures within one directory including at least a first file and a second file. The service data is grouped together in at least one service slot. Each service slot is divided into a profile part and a data part. Each profile part has a slot number and is arranged to function as an authorization mechanism. Each profile part is stored in the first file and comprises a unique application identifier. Each data part is at least partly stored in the second file and comprises data related to a given service. And the memory stores at least one key to protect write access to the first and second files. A secure application module and a terminal are also provided for controlling service actions to be carried out by the terminal on the integrated circuit card.

Abstract: A system and method for providing access to an encrypted communication involves recording the session during which the communication is encrypted, replaying the session to recover data used to recover a session key, accessing a server to retrieve secret information also used to generate the session key, and recreating the session key using the recovered data and secret information. The system and method includes provision for authenticating parties to the key recovery, protecting communications required to retrieve the secret key, and establishing a record of the key recovery to serve as an audit trail.

Abstract: Methods and apparatus are provided that implement digital signing and/or encryption for the electronic transmission, storage, and retrieval of authenticated documents and that enable the establishment of the identity of the originator of an electronic document and of the integrity of the information contained in such a document. Together these provide irrevocable proof of authenticity of the document. The methods and apparatus make it possible to provide “paper-less” commercial transactions, such as real-estate transactions and the financial transactions secured by real estate. A Certification Authority provides tools for initializing and managing the cryptographic material required to sign and seal electronic documents. An Authentication Center provides “third party” verification that a document is executed and transmitted by the document's originator. The methods and apparatus eliminate the need for “hard copies” of original documents as well as hard-copy storage.

Abstract: A quantum cryptographic key distribution (QKD) system splits discrete light signals from a laser source into a pair of light pulses that are orthogonally polarized with respect to each other, imparts a phase shift to one or both of these separate pulses during their round trip from the sender to the receiver and back, assures that the return pulses from the receiver are attenuated to single-photon pulses, recombines the phase-shifted pulses at the sender, and then detects from the recombined signal its polarization state, which is representative of the net phase shift imparted by the sender and receiver. The phase modulator at the receiver transmits only one polarization (e.g., vertical), but is used in a manner that permits it to equally modulate both polarization components of an arriving pulse. In this arrangement, when both components of a pulse reach the phase modulator at the receiver, they are both entirely vertically polarized and a phase shift is imparted at that time.