security against (someone or something)
Protection from someone or something; that which ensures the safety of someone or something from something else. Our antivirus software offers you security against all manner of malicious cyber-threats. The prisoner offered to testify in exchange for security against prison time. The entrances and exits have all been fitted with deadbolts and cameras to provide security against intruders.
security against something
something that keeps something safe; something that protects; a protection. Insurance provides security against the financial losses owing to theft, loss, or damage. A good education is a security against unemployment.