Abstract: Systems and methods are disclosed herein for managing group membership. To remove a user from a group, a group management system ensures that the device associated with the user is no longer able to decrypt messages that are sent by other devices in the group, in spite of having a copy of the binary tree associated with the group. Accordingly, the group management system may update private and public keys that the device may access while ensuring that other devices get the updated private and public keys. The group management system may manipulate the binary tree to move the root node and the sibling node of the node associated with the user being removed such that the update to the binary tree ensures the remaining group members are able to properly participate in future group update operation for which the binary tree may be necessary.

Abstract: An end-to-end mechanism is disclosed herein for transporting encrypted messages over hypertext transport protocol (HTTP) sent to a group of recipients. In particular, the disclosed mechanism receives a message (e.g., as an input from a user) and encrypts that message using an encryption mechanism with a key unique to a particular user and to the message (e.g., different messages are encrypted using different keys). The encrypted message is then stored in a generated object along with other metadata needed for message processing. Once the object is generated, it is signed and encoded into a binary representation that is then sent to a server. The server system receives the binary representation and decodes it back into the object. The metadata of the object is then used to route the message to the correct recipient applications for decryption.

Abstract: An objective of the present invention is to obtain a mutual authentication method in which mutual authentication is carried out securely and conveniently. In order to achieve the above objective, in the mutual authentication process, a private key K0, being an initial value, is stored in a client and a server (Pc0, Ps0). The client generates a random number R, calculates secret data C and authentication data A, and transmits the data items to the server (Pc1). The server receives the authentication data A and the secret data C from the client, and generates a random number Q, calculates secret data S, and authentication data B and returns the data items, as well as updating the private key K0 with a private key K1 (Ps1). The client receives from the server the authentication data B and the secret data S, generates the random number R, calculates secret data C2, authentication data A2, and returns the data items to the server, and updates the private key K0 with the private key K1(Pc2).

Abstract: A security system having two-way communication with a central monitoring station. The security system is equipped with a computerized control and communications unit. The control and communications unit is connected to a position determination device and to a calling unit. The control and communications unit is also connected to several intrusion detection devices. Upon direction of the control and communications unit, for example, in response to the detection of a violation of an intrusion detection device, the calling unit establishes a communications link with the central monitoring station and communicates thereto the status and location of the vehicle in which the security system is located. The control and communication device is operable to receive commands from a handset electrically connected thereto. The central monitoring station, by communicating with the control and communications unit, is operable to control functional units of the vehicle.

Abstract: A security system having two-way communication with a central monitoring station. The security system is equipped with a computerized control and communications unit. The control and communications unit is connected to a position determination device and to a calling unit. The control and communications unit is also connected to several intrusion detection devices. Upon direction of the control and communications unit, for example, in response to the detection of a violation of an intrusion detection device, the calling unit establishes a communications link with the central monitoring station and communicates thereto the status and location of the vehicle in which the security system is located. The control and communication device is operable to receive commands from a handset electrically connected thereto. The central monitoring station, by communicating with the control and communications unit, is operable to control functional units of the vehicle.

Abstract: A security system having two-way communication with a central monitoring station. The security system is equipped with a computerized control and communications unit. The control and communications unit is connected to a position determination device and to a calling unit. The control and communications unit is also connected to several intrusion detection devices. Upon direction of the control and communications unit, for example, in response to the detection of a violation of an intrusion detection device, the calling unit establishes a communications link with the central monitoring station and communicates thereto the status and location of the vehicle in which the security system is located. The control and communication device is operable to receive commands from a handset electrically connected thereto. The central monitoring station, by communicating with the control and communications unit, is operable to control functional units of the vehicle.