A method of device-to-device communications on a cellular licensed spectrum performed by a first user equipment, the method comprising: performing an authentication with a core network comprising a proximity services application server and a proximity services function server using a unique real identifier of the first user equipment, to allow the proximity services application server to offer device-to-device communications for the first user equipment; encrypting communication data based at least in part on a security policy associated with at least one of the following: a general trust evaluation, or a local trust evaluation; and sending the encrypted communication data to one or more second user equipments with device-to-device communication on the cellular licensed spectrum, wherein for the one or more second user equipments at least one of the following: a general trust evaluation result, or a local trust evaluation result, satisfies the security policy set by the first user equipment and is eligible to access the encrypted communication data, wherein the local trust evaluation result of the one or more second user equipments is evaluated at the first user equipment according to pseudonyms of the first user equipment and the one or more second user equipments, wherein the pseudonyms of the first user equipment and the one or more second user equipments are assigned by the proximity services function server, and wherein the general trust evaluation result of the one or more second user equipments is evaluated at the proximity services application server according to unique anonymous identifiers of the first user equipment and the one or more second user equipments. performing an authentication with a core network comprising a proximity services application server and a proximity services function server using a unique real identifier of the first user equipment, to allow the proximity services application server to offer device-to-device communications for the first user equipment; encrypting communication data based at least in part on a security policy associated with at least one of the following: a general trust evaluation, or a local trust evaluation; and sending the encrypted communication data to one or more second user equipments with device-to-device communication on the cellular licensed spectrum, wherein for the one or more second user equipments at least one of the following: a general trust evaluation result, or a local trust evaluation result, satisfies the security policy set by the first user equipment and is eligible to access the encrypted communication data, wherein the local trust evaluation result of the one or more second user equipments is evaluated at the first user equipment according to pseudonyms of the first user equipment and the one or more second user equipments, wherein the pseudonyms of the first user equipment and the one or more second user equipments are assigned by the proximity services function server, and wherein the general trust evaluation result of the one or more second user equipments is evaluated at the proximity services application server according to unique anonymous identifiers of the first user equipment and the one or more second user equipments.