Bulk Collection of Signals Intelligence: Technical Options by unknow

Author:unknow
Language: eng
Format: epub
Publisher: The National Academies Press
Published: 2015-03-26T00:00:00+00:00

3.2.4 How Metadata Are Used in Finding Alternate Identifiers

Finding alternate identifiers depends on collecting timely communications metadata in bulk. The collection must be in bulk in order for the metadata to include the new identifiers, which are not known at the time of collection to be associated with a target because they are two hops from the old identifier. Collection that is focused around the target (i.e., communications channels and modes that the target is known to use) is used, in part, to limit intrusion on innocents. Focus is also driven by concerns of cost and computer processing time to run the correlation algorithms.4

Note that the two-hop restriction announced by the President in January 2014 on queries of domestic telephone metadata still allows alternative identifiers to be found for known domestic reasonable and articulable suspicion (RAS) targets.5 Starting from a target, a query will find all the target’s one-hop contacts, then find all two-hop contacts; among these, there may be an identifier that communicates with many of the target’s one-hop contacts. This identifier may be an alternate identifier for the target.

Reverse targeting is another approach to find a target’s alternate identifiers by working backwards from persons known to be in contact with the target. In this approach, each identifier that communicates with the target is used as a query against bulk metadata or as a selector in future targeted collection, which will reveal any new identifier that communicates with the target’s previous communication partners. Because this method explicitly collects against persons known not to be persons of interest, apart from the fact that they communicate with the target, the use of this method raises extra privacy concerns. Current policy and statutes forbid the use of this method under certain authorities.6

Download

Copyright Disclaimer:
This site does not store any files on its server. We only index and link to content provided by other sites. Please contact the content providers to delete copyright contents if any and email us, we'll remove relevant links or contents immediately.