A network communication method comprises connecting, by a server and client, through networks and sharing a symmetric key, generating, by the server, a credential by which the client can be identified, through random number generation, and sharing the credential with the client, generating, by the client, transmission data containing a serial number indicating the sequence of the transmission data, and transmitting a message to the server, and generating, by the server, transmission data containing a serial number indicating the sequence of the transmission data, and transmitting a message to the client. Accordingly, the present invention has an advantage in that when a connection between a server and client is interrupted, the connection can be automatically recovered using a credential, by which a connected terminal can be identified in a network environment between the server and the client, without a separate process for authenticating a reconnected terminal.

System and method to protect the privacy of ADS-B messages transmitted by aircraft. The system includes one or more ground stations with a ground station control unit and a ground ADS-B transponder for receiving an ADS-B message. The ground station control unit includes an aircraft position determination module for retrieving an aircraft position included in the ADS-B message; an operating conditions module for determining the fulfillment of operating conditions including determining if the aircraft position is an actual aircraft position; and a fake aircraft position generator for computing one or more fake aircraft positions. The ground station control unit broadcasts one or more fake ADS-B messages including the fake aircraft positions if the operating conditions are met. With this system only trusted receivers can obtain the real position of the aircraft.

Disclosed herein are systems and method for preventing the spread of malware in a synchronized data network, the method including: receiving, at a first time by a server connected to a plurality of computing devices, a file from a first computing device; monitoring for changes to the file stored on the server; in response to detecting a change, generating a record indicative of the change to the file; receiving, at the server from a second computing device, a download request for the file at a second time; determining whether at least one record exists that indicates any change to the file between the first time and the second time; in response to determining that the record exists, scanning the file for malware; and in response to determining that the file stored on the server is associated with malware, denying the download request.

A system and method for encoding data by providing data expansion and compression functions for arbitrary input and output lengths. The input is partitioned into groups of sequential bits. A subkey is selected from secret key material for each group of the input bits. A tree of XOR gates applies XOR operations between the subkeys to generate the output. The XOR gates are arranged in layers and all the XOR gates within a layer switch at about the same time. A compression function is performed if the input length is greater than or equal to the output length and an expansion function is performed if the input length is less than or equal to the output length. There is no statistical correlation between the input and the output. A nonlinear function can be applied to the output such as an invertible S-Box, non-invertible S-Box, or series of Rotate-Add-XOR operations.

A system and method for encoding data by providing data expansion and compression functions for arbitrary input and output lengths. The input is partitioned into groups of sequential bits. A subkey is selected from secret key material for each group of the input bits. A tree of XOR gates applies XOR operations between the subkeys to generate the output. The XOR gates are arranged in layers and all the XOR gates within a layer switch at about the same time. A compression function is performed if the input length is greater than or equal to the output length and an expansion function is performed if the input length is less than or equal to the output length. There is no statistical correlation between the input and the output. A nonlinear function can be applied to the output such as an invertible S-Box, non-invertible S-Box, or series of Rotate-Add-XOR operations.

A data transfer process can include multiple verification features usable by a “source” device to ensure that a “destination” device is authorized to receive a requested data object. The source device and destination device can communicate via a first communication channel (which can be on a wide-area network) to exchange public keys, then use the public keys to verify their identities and establish a secure session on a second communication channel (which can be a local channel). The data object can be transferred via the secure session. Prior to sending the data object, the source device can perform secondary verification operations (in addition to the key exchange) to confirm the identity of the second device and/or the locality of the connection on the second communication channel.

An apparatus includes a processor and a memory operatively coupled to the processor and associated with an instance of a distributed database at a first compute device. The processor is configured to select an anonymous communication path. Each blinded public key from a sequence of blinded public keys associated with the anonymous communication path is associated with a pseudonym of a compute device from a set of compute devices that implement the anonymous communication path. The processor is configured to generate an encrypted message encrypted with a first blinded public key. The processor is configured to generate an encrypted data packet including the encrypted message and a compute device identifier associated with a second compute device. The encrypted data packet is encrypted with a second blinded public key. The processor is configured to send the encrypted data packet to a third compute device.

An apparatus includes a processor and a memory operatively coupled to the processor and associated with an instance of a distributed database at a first compute device. The processor is configured to select an anonymous communication path. Each blinded public key from a sequence of blinded public keys associated with the anonymous communication path is associated with a pseudonym of a compute device from a set of compute devices that implement the anonymous communication path. The processor is configured to generate an encrypted message encrypted with a first blinded public key. The processor is configured to generate an encrypted data packet including the encrypted message and a compute device identifier associated with a second compute device. The encrypted data packet is encrypted with a second blinded public key. The processor is configured to send the encrypted data packet to a third compute device.

Systems, methods, and non-transitory computer-readable storage media for rotating security keys for an online synchronized content management system client. A client having a first security key as an active security key may send a request to a server for a new security key as a replacement for the first security key. The server may receive the request and generate a candidate security key. The server can issue the candidate security key to the client device. After receiving the candidate security key, the client may send a key receipt confirmation message to the server. In response to the confirmation message, the server may mark the candidate key as the new security key for the client and discard the client's old security key. The server may send an acknowledgment message to the client device. In response, the client may also mark the candidate key as its new active key.

Systems, methods, and non-transitory computer-readable storage media for rotating security keys for an online synchronized content management system client. A client having a first security key as an active security key may send a request to a server for a new security key as a replacement for the first security key. The server may receive the request and generate a candidate security key. The server can issue the candidate security key to the client device. After receiving the candidate security key, the client may send a key receipt confirmation message to the server. In response to the confirmation message, the server may mark the candidate key as the new security key for the client and discard the client's old security key. The server may send an acknowledgment message to the client device. In response, the client may also mark the candidate key as its new active key.