The phrase "a time of security" is correct and usable in written English.
It can be used to describe a period characterized by safety, stability, or lack of threat.
Example: "After years of conflict, the nation finally entered a time of security, allowing its citizens to rebuild their lives."
Alternatives: "an era of safety" or "a period of stability."
Never mind his authoritarianism: His tenure was remembered as a time of security, prosperity and liberalism.
It is not clear why the US ambassador had returned to Benghazi at a time of security concerns.
Centre and right-wing parties argue the measures are needed to maintain Switzerland's army in a time of security challenges.
We must also meet a just and civilized standard for retirement, so that retirement is a time of security, not poverty.
In the instance of the school shooter, that spectacle, that it is such an intense spectacle for us, arises from something else we share with him: a clear understanding of childhood as a time of security, of schools as a site of safety and as society's organ for its own reproduction.
"The government is clear that, at a time of heightened security threat, it is essential our law enforcement and security and intelligence services have the power they need to keep people safe.
"At a time of increased security concerns over movements from Libya, this situation is abnormal.
But still, they said, they relished the chance to visit New York, even during a time of heightened security.
The violence came at a time of heightened security during India's general election, with voting taking place over six weeks.
"It is particularly troubling that this could happen at a time of heightened security," said Richard A. Brown, the Queens district attorney, whose office is prosecuting Mr. Slade.
The crash occurred during a time of heightened security and concern in newsrooms across the United States over speech and violence targeting the news media.
