Patent ID: 7729710

Claim:
A method for filtering spam directed at mobile phones in a short message system (SMS), said method comprising: receiving, by an authentication apparatus, a short message originating from a sending apparatus and directed to a destination mobile phone, wherein the sending apparatus is a sending mobile phone, wherein the short message received by the authentication apparatus comprises message content, a mobile phone number of the destination mobile phone, and a first authentication code of the destination mobile phone, wherein a second authentication code of the destination mobile phone is stored in a memory accessible to the authentication apparatus, and wherein the short message has not been delivered to the destination mobile phone when received by the authentication apparatus, extracting, by the authentication apparatus from the short message, the first authentication code of the destination mobile phone; extracting, by the authentication apparatus from the memory, the second authentication code of the destination mobile phone; ascertaining, by the authentication apparatus, that the extracted first authentication code matches the extracted second authentication code; after said ascertaining: determining that the short message is not SMS spam and not preventing the short message from being subsequently received by the destination mobile phone, said determining that the short message is not SMS spam and said not preventing being performed by the authentication apparatus, determining, by the authentication apparatus after said ascertaining, that an authentication service status of the sending apparatus is activated; and responsive to said determining that the authentication service status of the sending apparatus is activated, including, by the authentication apparatus, an authentication code of the sending mobile phone along with a mobile phone number of the sending phone in the short message, wherein the authentication code of the sending mobile phone in short message is appended to a back end of the mobile phone number of the sending mobile phone.