http://www.legislation.gov.uk/ukpga/2000/23/section/49/notesLegislationCrime and law enforcementPoliceCivil and human rightsPrivacy and data protectionExplanatory Notes to Regulation of Investigatory Powers Act 2000Home OfficeKing's Printer of Acts of Parliament2018-08-22 23 28 July 2000 255 This section introduces a power to enable properly authorised persons (such as members of the law enforcement, security and intelligence agencies) to serve notices on individuals or bodies requiring the disclosure of protected (e.g. encrypted) information which they lawfully hold, or are likely to, in an intelligible form. 256 Subsection (1) limits the information to which this power to serve notices applies. It does so by defining the various means by which the protected information in question has been, or is likely to be, lawfully obtained. By way of illustration, this could be material: seized under a judicial warrant (e.g. under the Police and Criminal Evidence Act 1984 (PACE)); intercepted under a warrant personally authorised by the Secretary of State under Chapter I of Part I of this Act; lawfully obtained under an authorisation given under Chapter II of Part I or Part II of this Act; lawfully obtained by an agency under their statutory functions but not under a warrant (e.g. under the Customs and Excise Management Act 1979); or which has lawfully come into the possession of an agency but not by use of statutory functions (e.g. material which has been voluntarily handed over). 257 Subsection (2) states that persons with the “appropriate permission” (see Schedule 2) may serve a notice imposing a disclosure requirement in respect of the protected information in question if there are reasonable grounds for believing: that the key to the relevant protected information is in the possession of the person on whom the notice is being served; that serving a notice imposing a disclosure requirement is necessary for the reasons set out in subsection (3), or necessary for securing the effective exercise or proper performance of any statutory power or duty of a public authority; that imposing a disclosure requirement is proportionate to what is sought to be achieved by doing so; and that an intelligible version of the relevant protected information cannot be obtained by any other reasonable means. key is defined in section 56(1) possession of a key is defined in section 56(2) 258 Subsection (4) explains the format which notices must take. 259 The effect of subsections (5) and (6) is that, where applicable, notices must be served on a senior officer within a corporate body or firm. 260 Subsection (7) states that the requirement in subsections (5) and (6) does not apply where there are special circumstances to the case which mean that the purposes for which a notice is given would be defeated if it was served on a senior officer in an organisation (e.g. where that senior officer is a suspect in a criminal investigation). 261 Subsection (8) specifies the persons to whom a disclosure may be made by the recipient of a notice. 262 Subsection (9) ensures that a key which has been used solely for the purpose of generating electronic signatures does not have to be disclosed in response to a notice. electronic signature is defined in section 56(1) 263 The effect of Schedule 2, which is introduced by subsection (11), is to set authorisation levels (described in Schedule 2) for permission to serve a notice under section 49. The level of authority required will vary depending on the power under which the protected information was, or is likely to be, lawfully obtained.