The use of cloud computing services is still increasing. However, confidentiality issues are considered as the main obstacles for a wide adoption of cloud computing facilities. The objective of this paper is to present the two competing interests at stake: data security and national security, and examine how both could be reconciled. The paper is structured in three distinct chapters where cloud computing services, encryption, and data protection will be adressed. A focus will also be drawn on EU Council proposal on encryption. Encryption techniques are an important tool that can guarantee data confidentiality, limiting the risk of data breaches, exposure of confidential data, and thus essential for customers, individuals or companies deploying cloud solutions at a large scale. As data security cannot be an excuse to form a threat to national security, the reverse should also be true: national security cannot be an excuse (and abused) in order to limit or circumvent data security.