The Hala Protocol

BP 9. Request the original copy and metadata of any audio data received from a third party source, if practicable

A collection effort may involve audio data received from third-party sources. For example, when third-party individuals or organisations on the ground in a conflict context do not have the capability to adequately store, process, or preserve the audio data they are collecting, they may elect to send the data to a Collector with these capabilities.

When Collectors receive audio data from third-party sources, they should consider taking steps to ensure the received audio data is neither enhanced nor degraded, whether by a third party or as a result of the transfer of the data. For example, data may be degraded if it has gone through data compression (see BP 18), or it may become degraded if the audio formatting used by the source and the Collector is incompatible. The Collector should aim to identify any such vulnerabilities that would cause the audio data, if put forth as evidence, to be considered inadmissible or be granted less weight if admitted. If such vulnerabilities exist, the Collector must clearly document them.1

Ideally prior to receipt of the audio, the Collector should consider requesting from the third-party source, if available:

  1. the original copy of audio data,
  2. sent via an end-to-end encrypted communication platform,
  3. inclusive of all available embedded metadata and associated metadata.

Embedded metadata
A digital asset may lose its embedded metadata when it is posted online or shared through some messaging services. The Collector should therefore:

  1. Request that the original copy of the audio data be sent through a communication channel that does not strip embedded metadata, where possible;
  2. Identify what metadata is embedded in the received audio data; and
  3. Verify the existing embedded metadata with the third-party source to identify any gaps or inconsistencies (see BP 8).

Associated metadata (discussed in greater detail in BP 17) The Collector’s inquiry to the third-party source should include, but is not limited to, a request for:

  1. Information about the collection process, such as who collected the audio, and for what purpose;
  2. The chain of custody of the audio data, inclusive of verification features such as the data’s cryptographic hash value or cryptographic signature;
  3. Any formal or informal notes taken in relation to the audio’s collection;
  4. Information about any storage, preservation, or enhancement processes applied to the audio data;
  5. Relevant information about the context within which the audio was collected; and
  6. If the audio includes human voice(s), the answers to the following questions: was the consent of the data subject(s) obtained? If not, why not? Is it possible, as well as appropriate from a security and ethical standpoint, to contact the data subject(s) to obtain their consent to transfer the audio?

Tech Specs & Resources

Techniques to share audio data without undermining its metadata include

  • using a sharing service that does not strip an audio file of its embedded metadata during transfer, e.g., ProtonDrive; and/or
  • wrapping the audio file(s) in a separate, non-destructive container, e.g., a ZIP or TAR archive, prior to sharing.

When using an instant messenger service, e.g., WhatsApp, sharing an audio file as a document attachment preserves embedded metadata.

For guidance on identifying and analysing an audio file’s metadata, see e.g., SWGDE Best Practices for Digital Audio Authentication (2018), Section 4.4. ‘Global Analyses’.

For guidance on reviewing audio data submitted by a third-party source, see e.g., SWGDE Best Practices for the Enhancement of Digital Audio (2020), paras. 2.1-2.4.

For guidance on cryptographically binding provenance metadata to a digital asset, see e.g., the Coalition for Content Provenance and Authenticity’s C2PA Technical Specification and C2PA Explainer.

Legal Framework

See section 4.2.3. on protecting the right to privacy when audio data was collected by a third party.

See section 5.2. and section 5.3. on the importance of accurately documenting the date and circumstances of the collection of information when establishing the relevance and probative value of evidence.

See also Prosecutor v Bemba (ICC), Public Redacted Version of “Decision on the Prosecution’s Application for Admission of Materials into Evidence Pursuant to Article 64(9) of the Rome Statute” of 6 September 2012, para. 84, wherein the Trial Chamber refers to the role of ‘date, circumstances and context in which the recording was created’ in establishing relevance and probative value.

Applicable Ethical Principles Legal Awareness; Accountability; Accuracy, Impartiality, and Objectivity.

Footnotes

  1. This is an extension of the requirement stated in BP 3 that Collector ‘personnel must at all times strive to document the collection effort in a manner that is as consistent, clear, and transparent as possible’: Prosecutor v Ongwen (ICC), Trial Judgment, para. 658; Prosecutor v Ongwen (ICC), Confirmation of Charges, para. 51; Prosecutor v Ongwen (ICC), Transcript, para. 44, lines 8-24; Prosecutor v Tolimir (ICTY), Judgment, para. 64, referring to Prosecutor v Tolimir (ICTY), Transcript, page 5033; Prosecutor v Blagojević and Jokić (ICTY), Decision on Admission of Intercept Materials, para. 21; Prosecutor v Katanga and Chui (ICC), Decision on Bar Table Motion, para 30. See the discussion in sections 5.2. and 5.3. of the Legal Framework. ↩