Abstract: The present application relates to a substrate, an LED light source assembly and manufacturing methods therefor. The substrate includes a first substrate and a second substrate which are arranged in a stacked manner. Electrode soldering regions on the front side of the first substrate and corresponding first conductive regions on the back side of the first substrate are electrically connected; and second conductive regions on the front side of the second substrate and corresponding third conductive regions on the back side of the second substrate are electrically connected, where the corresponding first conductive regions and the corresponding second conductive regions are electrically connected.

Abstract: Disclosed are a key management method and system. A master key is remotely downloaded to avoid the problem that the master key is not issued to a merchant until the master key needs be downloaded on a POS terminal, so as to reduce logistics costs and maintenance costs. When a key is remotely downloaded, a KMS system uses a symmetric algorithm to encrypt the key to be transmitted to ensure that the encrypted key can only be decrypted by a corresponding POS terminal, thereby ensuring the security of data transmission. During bidirectional authentication, an application program of the POS terminal can only contact an encrypted text form of the key instead of a plain text key needing to be remotely downloaded to the POS terminal, thereby ensuring security in reproduction.

Abstract: Disclosed are a key management method and system. A master key is remotely downloaded to avoid the problem that the master key is not issued to a merchant until the master key needs be downloaded on a POS terminal, so as to reduce logistics costs and maintenance costs. When a key is remotely downloaded, a KMS system uses a symmetric algorithm to encrypt the key to be transmitted to ensure that the encrypted key can only be decrypted by a corresponding POS terminal, thereby ensuring the security of data transmission. During bidirectional authentication, an application program of the POS terminal can only contact an encrypted text form of the key instead of a plain text key needing to be remotely downloaded to the POS terminal, thereby ensuring security in reproduction.