Methods and apparatuses for secure communication between a first and a second communication partner

A method for secure communication between a first and a second communication partner, comprising:

• establishing a communication link between the first and the second communication partner;
• determining one or more session identifiers by one of the first and the second communication partner for one or more subsequent secure communication sessions;
• communicating the one or more session identifiers to an other of the first and the second communication partner;
• determining, for each of the one or more session identifiers, a respective corresponding symmetric session key in each of the first and the second communication partner;
• and
• storing the one or more session identifiers and the corresponding symmetric session keys in each of the first and the second communication partner for one or more subsequent secure communication sessions;
• in the one or more subsequent secure communication sessions,
• selecting one of the stored session identifiers by one of the first and the second communication partner,
• communicating the selected session identifier to the other of the first and the second communication partner, and
• using the stored corresponding symmetric session key for the one or more subsequent secure communication sessions to secure communication between the first communication partner and the second communication partner,
• setting up a ranging procedure between the first communication partner and the second communication partner in the one or more subsequent secure communication sessions after using the stored corresponding symmetric session key to securely communicate between the first communication partner and the second communication partner,
• wherein the ranging procedure comprises determining a distance between the first and the second communication partner by measuring a time difference between a first time of sending a ranging signal from one of the first and the second communication partner to an other of the first and the second communication partner and a second time of receiving a response signal from the other of the first and the second communication partner.

An apparatus for secure communication, comprising:

• means for establishing a communication link between one communication partner and another communication partner;
• means for determining one or more session identifiers wherein the one or more session identifiers are different from a session identifier of the communication link;
• means for communicating the one or more session identifiers to the one communication partner using the communication link;
• means for determining, for each of the one or more session identifiers, a respective corresponding session-specific symmetric session key bound to the corresponding session identifiers;
• and
• means for storing the one or more session identifiers and the corresponding session-specific symmetric session keys for one or more subsequent new secure communication sessions.