Online gambling allows users to participate in mental games and bet over the Internet. It can open new opportunities for casinos to make more money; however, at the same time, there are a lot of security challenges. In this paper, we describe our scheme for secure online gambling and secure mental poker protocols over the Internet based on our previous researches. Our scheme provides both the fairness of online gambling processes and secure linking of the online gambling with payment. A unique link between payments and gambling outcome is provided so that the winner can be ensured to get the payment. The gambling games are generic in our fair online gambling scheme. Mental poker is one of most popular games of online gambling. In this paper, efficient and secure mental poker protocols are provided. These mental poker protocols are based on multiple encryption and decryption of individual cards. These protocols satisfy all major security requirements of a real mental poker. The card salesman has been got rid of and the minimal effect due to collusion has been guaranteed. These protocols are more efficient compared with other known protocols. The strategies of players can be kept confidential with the introduction of a dealer. These mental poker protocols are suitable for implementation in an online card game.