According to Richards and Solove the “right to privacy” as we now understand it actually grew out of an earlier recognition of the right to confidentiality in certain situations. Warren and Brandeis then took this original principle of confidentiality and shifted it to focus on a newly developed right to privacy.
United Kingdom
Secret evidence is incompatible with the rule of law
While the use of secret evidence may be acceptable initially (as part of an investigation or short-term detention while more evidence is gathered), the defense needs access to this evidence. Without it, any trial or legal process is simply unfair.