Evans also shared his thoughts on the much-debated Communications Data Bill, which will allow law enforcement agencies to monitor text messages and emails for anti-terrorism purposes.
"It would be extraordinary and self-defeating if terrorists and criminals were able to adopt new technologies in order to facilitate their activities while law enforcement and security agencies were not permitted to keep pace with those same technological changes," he said.
The Olympic Games present an attractive target for our enemies.
The speech also addressed the wider security threats the UK will face in the future and in the run up to this summer's London Olympics.
He revealed that Britain has faced a "credible terrorist attack plot" every year since 9/11, but stressed the Games do not represent an easy target.
"The Games present an attractive target for our enemies...and no doubt some terrorist networks have thought about whether they could pull off an attack," he said.
"But the Games are not an easy target and the fact we have disrupted multiple terrorist plots here and abroad in recent years demonstrates that the UK is not an easy target for terrorism."
Rob Cotton, chief executive of data protection software provider NCC Group, praised Evans for shedding light on the issue of cyber security, but said he should have backed up his statements with practical advice.
"Businesses need to know how they're at risk and what they can do to help themselves Jonathan Evans has given no practical advice," said Cotton.
"This is the job of the policy makers, who need to promote transparency from the top down. Whether that's through education, or government funding, businesses need more support."
