A content sharing method performed in a content redistribution device based on a non-realtime IPTV service includes transmitting a secret key in password information of a user of the content redistribution device to an IPTV service server and storing a public key corresponding to the secret key; and transmitting an event message for content request to the IPTV service server to request a non-realtime IPTV service. Further, the content sharing method includes receiving contents requested in the event message for content requesting from the IPTV service server; and decoding the received contents and encrypting the decoded contents using the public key. Furthermore, the content sharing method includes transmitting the contents encrypted using the public key to content recipient devices; and generating an event message for content sharing using the public key to transmit the generated event message to the content recipient devices.