Securetrade: a secure protocol based on transferable E-cash for exchanging cards in P2P trading card games.

Detalhes bibliográficos
Ano de defesa: 2016
Autor(a) principal: Silva, Marcos Vinicius Maciel da
Orientador(a): Não Informado pela instituição
Banca de defesa: Não Informado pela instituição
Tipo de documento: Dissertação
Tipo de acesso: Acesso aberto
Idioma: eng
Instituição de defesa: Biblioteca Digitais de Teses e Dissertações da USP
Programa de Pós-Graduação: Não Informado pela instituição
Departamento: Não Informado pela instituição
País: Não Informado pela instituição
Palavras-chave em Português:
Link de acesso: http://www.teses.usp.br/teses/disponiveis/3/3141/tde-22092016-113539/
Resumo: Trading card games (TCG) are distinct from traditional card games mainly because, in the former, the cards are not shared among players in a match. Instead, users play with the cards they own (e.g., that have been purchased or traded with other players), which correspond to a subset of all cards produced by the game provider. Even though most computer-based TCGs rely on a trusted third-party (TTP) for preventing cheating during trades, allowing them to securely do so in the absence of such entity, as in a Peer-to-Peer (P2P) scenario, remains a challenging task. Potential solutions for this challenge can be based on e-cash protocols, but not without adaptations, as those scenarios display different requirements: for example, TCGs should allow users to play with the cards under their possession, not only to be able to pass those cards over as with digital coins. In this work, we present and discuss the security requirements for allowing cards to be traded in TCGs and how they relate to e-cash. We then propose a concrete and efficient TTP-free protocol for trading cards in a privacy-preserving manner. The construction is based on a secure transferable e-cash protocol and on a P-signature scheme converted to the asymmetric pairing setting. According to our experimental results, the proposed protocol is quite efficient for use in practice: an entire deck is stored in less than 5 MB, while it takes a few seconds to be prepared for a match; the verification of the cards, on its turn, takes less time than an usual match, and can be performed in background while the game is played.