Abstract: A game system and game method wherein an e-ticket is displayed before the start of a game and contains a plurality of game indexes, an open code containing encrypted information about a combination of winning indexes stored on a game server, and information about prizes for a successful search. The user identifies the game indexes in the e-ticket and sends the indexes from the terminal to the game server. The game server compares the indexes, determines the result of the game, and sends an e-coupon to the terminal containing the indexes, the result of the game and an encryption key. The e-coupon allows the user to obtain their prize and/or check on a public resource that the result of encrypting the combination of winning indexes using the aforesaid key matches the open code, and that any alteration of the key and/or the combination of winning indexes corrupts the open code.