According to John Perryman, a senior historian with the Royal Australian Navy, an impenetrable wall of secrecy surrounded the sinking of the Sydney because of war-time security concerns.

据澳大利亚皇家海军的资深历史学家约翰·佩里曼所说，出于战时安全考虑，悉尼号沉没的秘密被一堵不可逾越的墙挡住了。

youdao

I'm just saying that in general, secrecy about how your security system works does not improve security, but rather usually the reverse.

我只是要说，通常情况下对安全系统的运作方式保密并不会提高安全，事实恰恰相反。

youdao

We will intensify our information security and secrecy, and improve management of information networks.

加强信息安全和保密工作，完善信息网络管理。

youdao

You claim that I ignore national security and other legitimate secrecy needs.

ECONOMIST: Privacy's end?

The document was demanded by lawmakers, mainly Democrats concerned about secrecy in national security decision making, before Brennan's hearing.

CNN: STORY HIGHLIGHTS

These days complete secrecy and heavy security - armoured cars and police helicopters - are needed to minimise the risk to a prime minister visiting Tripoli: even one regarded as a liberator.

BBC: Appealing to the people