Abstract: A method and device for issuing an identity certificate to a blockchain node in a blockchain network includes issuing a first identity certificate to a first terminal. a second identity certificate issuance request that is from the first terminal and that is made by using the first identity certificate is received and a second identity certificate is issued to the first terminal, which forwards the second identity certificate to a second terminal. A third identity certificate issuance request that is from the second terminal and that is made by using the second identity certificate is received and a third identity certificate is issued to the second terminal, which forwards the third identity certificate to a third terminal.

Abstract: A digital photo frame having dual display panels of the present invention includes a frame body, a foot, a microprocessor, an output and input interface, an external connecting storage device, a multiplexer, a first buffer unit, a second buffer unit, a third buffer unit, a first display panel, a second display panel and a control panel. When a portrait mode photo is desired to be displayed, the microprocessor sends the photo to the first buffer and to display the photo in the first display panel. When a landscape mode photo is desired to be displayed, the microprocessor sends the photo to the second buffer and to display the photo in the second display panel. Hence the present invention can avoid incorrect display ratio of the photos.