Large-scale rumor spreading could pose severe social and economic
damages. The emergence of online social networks along with the
new media can even make rumor spreading more severe. Effec-
tive control of rumor spreading is of theoretical and practical sig-
nificance. This paper takes the first step to understand how the
blockchain technology can help limit the spread of rumors. Specif-
ically, we develop a new paradigm for social networks embedded
with the blockchain technology, which employs decentralized con-
tracts to motivate trust networks as well as secure information ex-
change contract. We design a blockchain-based sequential algo-
rithm which utilizes virtual information credits for each peer-to-
peer information exchange. We validate the effectiveness of the
blockchain-enabled social network on limiting the rumor spread-
ing. Simulation results validate our algorithm design in avoiding
rapid and intense rumor spreading, and motivate better mechanism
design for trusted social networks.