When competing in eBay bidding, online games or e-exams in embedded computing environments, people naturally face asynchronous starts from different computing devices, which is treated as a security risk of online contests. The security risks of online contest also include eavesdropping during data transmission without intended rights, and false start by malicious competitors, which also means asynchrony in contests. Accordingly, online contests need security guarantee especially on synchronization. In this paper, for synchronic and secure start in a contest, we update security requirements of confidentiality, anonymity and synchrony comparing to our previous work. Based on the updated requirements, we propose a general framework of Advanced Secure Synchronized Reading (ASSR) system that can hold multiple contests simultaneously by Cloud. Importantly, the system can ignore the impacts of heterogeneity among competitors. Considering the heterogeneity both on transmission and computing, we construct a novel Randomnessreused Identity Based Key Encapsulation Mechanism (RIBKEM) to support separable decapsulation, which can shorten both decryption delay and transmission delay with the best efforts. Finally, ASSR enhances synchronization achievement for contests start with heterogeneous delays of competitors while satisfying other security requirements. As a complement, the analysis on the provable security of ASSR is given, as well as a further analysis on the achievement of synchronization.