Abstract: A message hop-based communication method of guaranteeing real-time communication in a vehicle communication environment may comprise: receiving, by a first on-board unit (OBU) of a first vehicle, a first message including a message frame (MF) for probe vehicle data (PVD) from a road side unit (RSU); and transmitting a second message, including an MF for a basic safety message (BSM), to a second OBU of a second vehicle, the second message corresponding to the first message, wherein the PVD and the BSM each comprise a data frame for a hopping request.

Abstract: An information protection method based on software-defined perimeter (SDP) for Internet of Things (IoT) cloud security may comprise: receiving, at an SDP controller, an onboarding request message with an identity (ID) token from an SDP client acting as an initiating host, the onboarding request message comprising information requesting authentication of the SDP client and a handshake parameter specifying a handshake protocol for use in an SDP access process; and issuing, at the SDP controller, an SDP client credential corresponding to the handshake parameter.

Abstract: Provided are a driving negotiation method and apparatus for supporting stability against a blind spot, an unexpected situation, etc. and a rapid judgment and response of an autonomous vehicle in various driving environments. The driving negotiation apparatus includes a wireless communication module configured to support vehicle to everything (V2X) communication and at least one processor connected to the wireless communication module. The at least one processor receives a cooperative request message from a first vehicle, broadcasts a cooperative request message and additional information required for a negotiation to surrounding vehicles, receives a cooperative response message from at least one second vehicle among the surrounding vehicles, and transmits a message indicating that the negotiation is possible or impossible to the first vehicle on the basis of the cooperative response message.

Abstract: An encryption key management method includes: receiving a data registration request from a supplier terminal, determining a data identifier associated with the content data, encrypting a master key with a public key of the supplier terminal, and providing the supplier terminal with the master key encrypted with the public key of the supplier terminal, the data identifier, and a key update count value; receiving a subscription application related to the data identifier from a first subscriber terminal, encrypting the master key with a public key of the first subscriber terminal, and providing the first subscriber terminal with the master key encrypted with the public key of the first subscriber terminal and the key update count value; receiving encrypted content data encrypted with the symmetric key and a hash for the content data from the supplier terminal; and transmitting the encrypted content data and the hash to the first subscriber terminal.

Abstract: A Merkle tree-based data management method may comprise: aligning data into two-dimensional square matrix; calculating a hash value of each node of the two-dimensional square matrix; calculating hash values of each row of the two-dimensional square matrix; generating an additional column with nodes having the hash values of each row; calculating hash values of each column of the two-dimensional square matrix; generating an additional row with nodes having hash values of each column; and calculating a Merkle root by concatenating the hash values of the additional column and the hash values of the additional row.