  Owing to the meteoric rise in the usage of cryptocurrencies, there has been a
widespread adaptation of traditional financial applications such as lending,
borrowing, margin trading, and more, to the cryptocurrency realm. In some
cases, the inherently transparent and unregulated nature of cryptocurrencies
leads to attacks on users of these applications. One such attack is
frontrunning, where a malicious entity leverages the knowledge of currently
unprocessed financial transactions submitted by users and attempts to get its
own transaction(s) executed ahead of the unprocessed ones. The consequences of
this can be financial loss, inaccurate transactions, and even exposure to more
attacks. We propose FIRST, a framework that prevents frontrunning attacks, and
is built using cryptographic protocols including verifiable delay functions and
aggregate signatures. In our design, we have a federated setup for generating
the public parameters of the VDF, thus removing the need for a single trusted
setup. We formally analyze FIRST, prove its security using the Universal
Composability framework and experimentally demonstrate the effectiveness of
FIRST.
