  Today Internet is experiencing a massive number of users with a continuously
increasing need for data, which is the leading cause of introduced limitations
among security and privacy issues. To overcome these limitations, a shift from
host-centric to data-centric is proposed, and in this context,
Information-Centric Networking (ICN) represents a promising solution.
Nevertheless, unsettling the current Internet network layer, i.e., Internet
Protocol (IP), with ICN is a challenging, expensive task since it requires
worldwide coordination among Internet Service Providers (ISPs), backbone, and
Autonomous Services (AS). Therefore, researchers foresee that the replacement
process of the current Internet will transition through the coexistence of IP
and ICN. In this perspective, novel architectures combine IP and ICN protocols.
However, only a few of the proposed architectures place the security-by-design
feature. Therefore, this article provides the first comprehensive Security and
Privacy (SP) analysis of the state-of-the-art IP-ICN coexistence architectures
by horizontally comparing the SP features among three deployment approaches,
i.e., overlay, underlay, and hybrid, and vertically comparing among the ten
considered SP features. Lastly, the article sheds light on the open issues and
possible future directions for IP-ICN coexistence. Our analysis shows that most
architectures fail to provide several SP features, including data and traffic
flow confidentiality, availability, and anonymity of communication. Thus, this
article shows the secure combination of current and future protocol stacks
during the coexistence phase that the Internet will definitely walk across.
