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recalled the improperly shared CDR information. No additional improper access occurred
during the duration of the program.
2. (U) Data-Integrity Issues
(U) Beginning in 2017 and continuing until the program’s suspension in 2019, NSA
sought to diagnose and overcome complex data-integrity issues in the CDRs produced by phone
companies, which implicated a large number of records. 115 The government’s notices to the
FISA court described these issues. This section summarizes NSA’s repeated discovery of
anomalies in the data it received and the agency’s response to these incidents.
a. (U) Production of Inaccurate First-Hop Numbers
(TS//SI//NF) In the first data-integrity incident, a provider produced inaccurate first-hop
numbers to NSA in a subset of CDRs. The provider’s system had been incorrectly populating
terminating numbers (the field for a number used by the party receiving a call) with
While System 1 was designed to detect data which may not be authorized for collection, these
non-responsive similarly to data regularly
accepted by System 1. Accordingly, the system did not reject the data and instead requested
second-hop records using the erroneous first-hop response. As a consequence, NSA requested
records numbers “one hop” away from the .
(TS//SI//NF) While investigating this incident, the provider identified a separate incident:
records incorrectly produced to NSA as a result of a
. This error was separate from the errors related to the
.
(TS//SI//NF) The provider implemented a technical solution to prevent incorrect CDRs
from being delivered to NSA. NSA identified and purged CDRs that contained these
terminating numbers. NSA did not identify any incorrect CDRs that were used in
an application to the FISA court or as the source of reporting.
b. (TS//SI//NF) Production of Inaccurate Data Associated with
(TS//SI//NF) In another data-integrity incident, a provider produced to NSA almost
CDRs with inaccurate data. The inaccurate data was populated by the
provider’s CDR production system, which assembles the data into CDRs,
Specifically, when
. These
inaccurate CDRs were created by the provider’s CDR production system over a two year period.
115 (U) This large number of records reflected a fraction of one percent of the overall collection.
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