摘要 |
An encrypted broadcast messaging system (102, 103) determines the management crypto-keys held by each selected subscriber (101) device and not held by each excluded subscriber device of a group. The private message is decomposed into message-parts, one message-part per an excluded subscriber device, each message-part intended to be encrypted using each management crypto-key held by the selected subscriber devices (101) and not held by the excluded subscriber device. Each message-part is encrypted using the management crypto-keys, and delivered to at least the selected subscriber devices, identifying the message-parts delivered and the message-parts necessary to re-compose the private message. Each received encrypted message-parts necessary to re-compose the private message. Each received encrypted message-part is decrypted using the intended management crypto-key, and the necessary message-parts are chosen from which the private message is re-composed by combining in the selected subscriber device (101). |