Adrian Price, speaking at Infosecurity 2013, said that the biggest concern from cyber criminals for UK defence were from intrusions. He said that hacktivists such as Anonymous, as well as foreign intelligence, were constantly trying to break into its systems to get information useful for their causes.
He said, "It is particularly vital that we protect this information due to the national security implications, and more importantly, international relations with our allies.
"There is also a potential insider threat as well - for ideological reasons people might wish to hand state information to foreign governments. This is something we take very seriously."
"Obviously at the moment with our current operations in Afghanistan, if we do lose very sensitive military information, the impact is potentially wholesale loss of life. That is something we clearly wish to avoid."
Misha Glenny, a writer and broadcaster specialising in security speaking on the same panel as Price, said that the threats and techniques used had not changed a lot since the late 90's.
He said, "Phishing and social engineering are still a popular way of getting into a network system. DDoS attacks which the hacktivists like are still very popular. Then you have database intrusions, SQL injections and so on.
"It is pretty much the standard toolkit. What has changed is the environment that all this takes place in. You have many more actors involved.
"In the last five years there's no question we've seen an increase in sophisticated commercial cyber espionage, sometimes done by state backing, sometimes done by commercial competitors."