A method of playing back streaming content includes decoding the content based on a first decryption circuit configured based on a first key and outputting the content; requesting a second key from a server; receiving the second key and configuring a second decryption circuit based on the second key; and decoding the content based on a second decryption circuit and outputting the content, wherein the decoding of the content based on the first decryption circuit and outputting the content is performed until the second decryption circuit is configured.