  The video footage produced by the surveillance cameras is an important
evidence to support criminal investigations. Video evidence can be sourced from
public (trusted) as well as private (untrusted) surveillance systems. This
raises the issue of establishing integrity and auditability for information
provided by the untrusted video sources. In this paper, we focus on a airport
ecosystem, where multiple entities with varying levels of trust are involved in
producing and exchanging video surveillance information. We present a framework
to ensure the data integrity of the stored videos, allowing authorities to
validate whether video footage has not been tampered. Our proposal uses a
lightweight blockchain technology to store the video metadata as blockchain
transactions to support the validation of video integrity. The proposed
framework also ensures video auditability and non-repudiation. Our evaluations
show that the overhead introduced by employing the blockchain to create and
query the transactions introduces a very minor latency of a few milliseconds.
