highly confidential

基本解释

It was highly confidential.
这是高度机密的。
Nearly every page is stamped "highly confidential safeguards sensitive".
但是，几乎每页上都注明有“高度机密敏感的安全设施”。
For example, be cautious about storing highly confidential information in the HTTP Session object, as this object may be serialized to the database.
例如，对在 HTTP Session 对象中存储高度机密的信息要十分谨慎，因为此对象可能被序列化到数据库中。

This level of approval only comes following a process which is rigorous and absolutely necessary given the highly confidential nature of the communications being transmitted.
ENGADGET: BlackBerry 10 not secure enough for UK government workers -- yet (updated: GCHQ responds)
In general, employers conduct these checks for job seekers applying for positions with financial responsibility, for senior executive positions, and for those positions with access to highly confidential employee information, according to the report.
FORBES: Has Your Credit Report Cost You A Job?
The operation apparently compromised massive amounts of highly-confidential and classified information, including high-value trade and technology secrets.
FORBES: Connect