Drawing on original research and resources, this report reframes the challenges for identifying and protecting children as a result of the migration crisis in the Middle East and Europe, as well as the ensuing risks of trafficking and abuse. It discusses new approaches to the identification of children and highlights the important role that existing and emergent technologies, such as the blockchain technology, can play in asserting their identities. The report concludes with recommendations for further research and lists some immediate actions that would be needed to turn these ‘invisible’ children into invincible ones.