  Attacks targeting several millions of non-internet based application users
are on the rise. These applications such as SMS and USSD typically do not
benefit from existing multi-factor authentication methods due to the nature of
their interaction interfaces and mode of operations. To address this problem,
we propose an approach that augments blockchain with multi-factor
authentication based on evidence from blockchain transactions combined with
risk analysis. A profile of how a user performs transactions is built overtime
and is used to analyse the risk level of each new transaction. If a transaction
is flagged as high risk, we generate n-factor layers of authentication using
past endorsed blockchain transactions. A demonstration of how we used the
proposed approach to authenticate critical financial transactions in a
blockchain-based asset financing platform is also discussed.
