ProSecutor: Protecting Mobile AIGC Services on Two-Layer Blockchain via Reputation and Contract Theoretic Approaches

Mobile AI-Generated Content (AIGC) has achieved great attention in unleashing the power of generative AI and scaling the AIGC services. By employing numerous Mobile AIGC Service Providers (MASPs), ubiquitous and low-latency AIGC services for clients can be realized. Nonetheless, the interactions between clients and MASPs in public mobile networks, pertaining to three key mechanisms, namely MASP selection, payment scheme, and fee-ownership transfer, are unprotected. In this paper, we design the above mechanisms in a systematic approach and present the first blockchain to protect mobile AIGC, called <inline-formula><tex-math notation="LaTeX">${\sf ProSecutor}$</tex-math><alternatives><mml:math><mml:mi mathvariant="sans-serif">ProSecutor</mml:mi></mml:math><inline-graphic xlink:href="kang-ieq1-3390208.gif"/></alternatives></inline-formula>. Specifically, by roll-up and layer-2 channels, <inline-formula><tex-math notation="LaTeX">${\sf ProSecutor}$</tex-math><alternatives><mml:math><mml:mi mathvariant="sans-serif">ProSecutor</mml:mi></mml:math><inline-graphic xlink:href="kang-ieq2-3390208.gif"/></alternatives></inline-formula> forms a two-layer architecture, realizing tamper-proof data recording and atomic fee-ownership transfer with high resource efficiency. Then, we present the Objective-Subjective Service Assessment (<inline-formula><tex-math notation="LaTeX">$\text{OS}^{2}\mathrm{A}$</tex-math><alternatives><mml:math><mml:mrow><mml:msup><mml:mtext>OS</mml:mtext><mml:mn>2</mml:mn></mml:msup><mml:mi mathvariant="normal">A</mml:mi></mml:mrow></mml:math><inline-graphic xlink:href="kang-ieq3-3390208.gif"/></alternatives></inline-formula>) framework, which effectively evaluates the AIGC services by fusing the objective service quality with the reputation-based subjective experience of the service outcome (i.e., AIGC outputs). Deploying <inline-formula><tex-math notation="LaTeX">$\text{OS}^{2}\mathrm{A}$</tex-math><alternatives><mml:math><mml:mrow><mml:msup><mml:mtext>OS</mml:mtext><mml:mn>2</mml:mn></mml:msup><mml:mi mathvariant="normal">A</mml:mi></mml:mrow></mml:math><inline-graphic xlink:href="kang-ieq4-3390208.gif"/></alternatives></inline-formula> on <inline-formula><tex-math notation="LaTeX">${\sf ProSecutor}$</tex-math><alternatives><mml:math><mml:mi mathvariant="sans-serif">ProSecutor</mml:mi></mml:math><inline-graphic xlink:href="kang-ieq5-3390208.gif"/></alternatives></inline-formula>, firstly, the MASP selection can be realized by sorting the reputation. Afterward, the contract theory is adopted to optimize the payment scheme and help clients avoid moral hazards in mobile networks. We implement the prototype of <inline-formula><tex-math notation="LaTeX">${\sf ProSecutor}$</tex-math><alternatives><mml:math><mml:mi mathvariant="sans-serif">ProSecutor</mml:mi></mml:math><inline-graphic xlink:href="kang-ieq6-3390208.gif"/></alternatives></inline-formula> on BlockEmulator. Extensive experiments demonstrate that <inline-formula><tex-math notation="LaTeX">${\sf ProSecutor}$</tex-math><alternatives><mml:math><mml:mi mathvariant="sans-serif">ProSecutor</mml:mi></mml:math><inline-graphic xlink:href="kang-ieq7-3390208.gif"/></alternatives></inline-formula> achieves 12.5× throughput and saves 67.5% storage resources compared with BlockEmulator. Moreover, the effectiveness and efficiency of the proposed mechanisms are validated.