269.The effect of Subsections (4) and (5) is that where a person served with a notice is entitled or obliged to disclose a key, they need only provide those keys which are sufficient to access the relevant information and to put it into intelligible form. And Subsection (6) further provides that such a person may choose which keys to provide, so long as they suffice to access the information and render it intelligible.
270.Subsection (7) requires a person served with a notice to disclose every key to the relevant protected information that is in their possession, subject to the provisions in subsections (5) and (6). It means that a person need only provide those keys which suffice to access the information and render it intelligible, and that they may choose which keys to provide to achieve that end.
271.The effect of Subsection (8) is that where a person served with a notice no longer possesses a key to the relevant protected information, they are to disclose all information that is in their possession that would facilitate the discovery of the key.
Other Authorisations Part Iii:  Investigation of Electronic Data Protected by Encryption Etc Relevant time is defined in section 50(10)