But officials acknowledge that devising new procedures with tighter secrecy is likely to take months.

The unit's operations are now shrouded in even tighter secrecy.

To be sure, the strategy of tight secrecy and surprise was not always an Apple trademark.

America's jet project was initiated under the tightest possible secrecy.

She tried to find out what role Mr. Hopkins would play, but met with tight secrecy.

The group operated in tight secrecy and were using code words in their communication.

We've kept your presence under the tightest secrecy.

Since the transfer the unit's operations are said to have been shrouded in even tighter secrecy.

Development began in 1997 and was kept under tight secrecy, for many years the weapon's manufacturers refused to acknowledge its existence.

The grave design process was placed under tight secrecy.