July 14, 2018

Collection of domestic phone records under the USA FREEDOM Act

(Updated: July 15, 2018)

One of the most controversial NSA programs revealed by Edward Snowden was the bulk collection of domestic telephone records under the authority of Section 215 of the USA PATRIOT Act. A detailed analysis of the workings of this program was published on this weblog earlier.

In 2015, Section 215 was replaced by the USA FREEDOM Act, which prohibited the collection in bulk and provided more safeguards. The NSA became much more transparant about this program, which gives the opportunity for the following explanation of how the domestic phone records program currently works.

NSA is also more transparant about things going wrong: last month it revealed that it had to delete all the telephone records collected since 2015 due to technical irregularities.



Screenshot from 60 Minutes from December 15, 2013, showing an NSA contact chaining tool
used for the telephone records collected under Section 215.



Collection under Section 215 USA PATRIOT Act


The NSA started its bulk collection of domestic telephone metadata as part of the President's Surveillance Program (PSP), which president George W. Bush authorized in secret right after the 9/11 attacks. Its purpose was not to spy on random Americans, but to find connections between foreign terrorists and conspirators inside the US.

In May 2006, this bulk collection was brought from the president's authority under that of the FISA Court, based upon a very extensive interpretation of Section 215 of the USA PATRIOT Act. Internally, NSA refers to this kind of collection as BR FISA, with BR for Business Records.


Under Section 215, NSA collected domestic phone records from the three biggest American telecommunication companies: AT&T, Verizon and Sprint. According to government officials, the data provided by these companies consisted mostly of landline phone records, which meant that NSA actually got less than 30% of the total amount of US telephone metadata.

However, as of August 29, 2011, AT&T started to provide cell phone metadata too: ca. 1,1 billion records a day, which would make over 30 billion records each month. Before these records were handed over to NSA, AT&T stripped off the location data, to comply with the FISA Court orders that don't allow the collection of location data. Verizon was apparently not able or not willing to strip the location metadata, so their cell phone records could not be acquired by NSA.

To put these numbers in perspective: with a wireless communications market share of 32% for AT&T, the total number of cell phone metadata for the US would equal roughly 94 billion a month. During the first half of 2012, the NSA's total collection of foreign telephone metadata was 135 billion records a month. In January 2013, mobile phone calls in the Netherlands generated some 7.65 billion records a month.


At NSA, the domestic phone records were forwarded to MAINWAY, which is a centralized system for "contact chaining to identify targets of interest." MAINWAY not only contains domestic telephone metadata, but also foreign telephone and internet metadata, collected both inside and outside the US. Putting both foreign and domestic metadata in one system, allows finding as many connections as possible.

See for more:
- How NSA contact chaining combines domestic and foreign phone records
- Section 215 bulk telephone records and the MAINWAY database




Collection under the USA FREEDOM Act


Because the bulk collection under Section 215 was often regarded unconstitutional, the program was terminated as of November 2015 and replaced by the USA FREEDOM Act (USAFA), which was incorporated in Title V of the Foreign Intelligence Surveillance Act (FISA). Under this new authority, bulk collection of domestic phone records is not allowed anymore.

Instead, NSA can request only those records that contain phone numbers that have been in contact with an approved "seed" number. This means that all the American telecoms now have to hand over the matching results from both landline and cellphone calls, so it's a much larger pool compared to the situation under Section 215.


How this current domestic phone records program works is explained in remarkable detail in the transparancy report of the NSA Civil Liberties and Privacy Office (CLPO) from January 2016, as well as in the Annual Statistical Transparancy Report from the Office of the Director of National Intelligence (ODNI).

The statistical report for 2017 was published last April and also contains a lot of information about traditional FISA and Section 702 FAA (PRISM and Upstream) collection.



Overview of NSA's collection of domestic phone records under the USA FREEDOM Act
(source: NSA Transparancy Report - click to enlarge)


Seed numbers

The process starts with selecting specific targets and the phone numbers ("selectors") they use. Through the FBI and the Department of Justice, these selectors are submitted to the FISA Court (FISC), which determines whether there's a Reasonable, Articulable Suspicion (RAS) that these numbers are associated with foreign intelligence agents or people engaged in international terrorism. Under Section 215, the RAS was determined by one of 22 designated NSA officials.

After the FISC has approved these numbers, it issues individual orders approving the submission of these specific selectors to the telecommunications providers, and directing those providers to hand over the associated metadata to the proper government agency. According to the ODNI statistical report for 2017, the FISC issued orders for 42 targets in 2016 and for 40 targets last year.

The report doesn't mention the total number of selectors used by these targets. It's these selectors, phone numbers and maybe similar identifiers, that NSA uses as a "seed" to start creating a so-called contact chain. For earlier years, the total numbers of seed selectors were as follows (it's not known how many of these belonged to Americans):

2012 2013 2014 2015
288 423 161 56


Business records

At NSA, the RAS-approved selectors are entered into what is publicly called the "Enterprise Architecture", but which actually must be the MAINWAY contact chaining system. This returns any selectors from NSA's existing metadata collection that have been in direct contact with the RAS-approved seed selector.

Both the RAS-approved seed selectors and the connected ones from NSA's existing collection are then submitted to the telecommunications providers. They will query their databases of business records for those that contain any of the submitted phone numbers. The results are returned to the NSA, which lets them pass various validation steps, applies data tags and forwards them to the MAINWAY system.

Because a FISC order is valid for up to 180 days, the selectors can be submitted multiple times during that period in order to caputure any new matching records. These business records, or Call Detail Records (CDRs) are defined as "session identifying information" and include:
- Originating telephone number
- Terminating telephone number
- International Mobile Subscriber Identity (IMSI) number
- International Mobile Station Equipment Identity (IMEI) number
- Telephone calling card number
- Time and duration of a call
NSA is not allowed to receive the content of any communication, the name, address, or financial information of a subscriber or customer, or the cell site location or Global Positioning System (GPS) coordinates.
 

Contact chaining

The ODNI statistical transparancy report from April has a nice graphic that shows how to count the number of business records that the telecoms provide to the NSA:



Example of contact chaining of telephone metadata under the USA FREEDOM Act
(source: ODNI Transparancy Report - click to enlarge)


We see that the RAS-approved seed phone (number) can be in direct contact with a certain number of other phones, which is called the "first hop". Additionally, the providers also have to look for the phones that have been in contact with those first hop phones. This step is called the "second hop". A third hop is prohibited by law, but NSA analysts also determined that a third step is not analytically useful.

This way of contact chaining by linking phone numbers that have been in contact with each other may already be familiar from the reportings about the Section 215 program.

But the graphic also shows something that was rarely made clear: the business records collected by NSA are not just the phone numbers. Two phone numbers that have been in contact with eachother will usually have done so more than once (except for so-called "burner phones" that are intentionally used for one call only).

So for each pair of phone numbers, there can be a lot of records, at least one record generated per phone call or text message, both for the person calling and the person called. The example in the graphic shows 7 phones that produce 6000 call detail records (CDRs) during a certain period of time. This is something to keep in mind when it comes to the huge numbers of metadata collected by NSA.


Number of records

The ODNI transparancy report also provides the real numbers of telephone records collected by NSA under the authority of the USA FREEDOM Act. Although NSA is required by law to provide the annual number of "unique identifiers", the agency doesn't has the technical ability to isolate these unique identifiers within records received from the providers. This means that every single record is counted, even if the same record is received multiple times from one or multiple providers.

The report also explicitly says that the results of contact chaining will likely include both foreign and domestic phone numbers: "while the records are received from domestic communications service providers, the records received are for domestic and foreign numbers." Also, the targeted seed number could be a foreign number, which in the first hop could have called a foreign number, that in its turn could have called another foreign number in the second hop.


With that in mind, the report says that in 2016, the telecommunications providers handed over 151.230.968 phone records to NSA. In 2017 they did so for 534.396.285 records, which is not only a dramatic increase compared to the previous year, but also a probably unexpectedly high number for the just 40 targets approved by the FISA Court.

However, if each of these 40 targets called 50 numbers, and those numbers were also in contact with 50 numbers, we get some 100.000 phone numbers. Let's assume each pair of numbers was involved in 500 calls (or text messages), we already have 50.000.000 records. And this is still without duplicate records, like from multiple providers or recurring requests.


The large increase compared to 2016 may have been caused by a variety of factors, according to Alex Joel, ODNI's chief civil liberties officer: changes in the amount of historical data companies are choosing to keep; the number of phone accounts used by each target and changes to how the telecommunications industry creates records based on constantly shifting technology and practices.


Retention

These domestic call detail records may not be stored for more than 5 years after they were initially delivered to NSA. In addition, the minimization procedures require NSA to destroy promptly any records that are determined not to contain foreign intelligence information. Phone records that have been "the basis of a properly approved dissemination of foreign intelligence information" may be retained by NSA indefinitely.

After these records have been received and stored, they may also be queried, including using search terms associated with US persons. In 2016, NSA used ca. 22.360 search terms for such queries, while in 2017 that number had risen to 31.196.


Deletion

Recently, it turned out that the practical implementation of the collection of domestic phone records under the USA FREEDOM Act is apparently not that easy: in a remarkable public statement from June 28, 2018, NSA revealed that several months earlier, "analysts noted technical irregularities in some data received from telecommunications service providers."

These irregularities occurred in a number of Call Detail Records (CDRs), which meant that NSA was not legally authorized to receive them in that form. It appeared infeasible to identify and isolate the properly produced data, so NSA concluded that it should not use any of these records.


Subsequently, the agency began deleting all the phone records they had acquired since 2015. According to the statement, NSA meanwhile addressed the root cause of the problem for future CDR acquisitions. Civil liberties blogger emptywheel suggests that the records may have contained content or location data, but NSA spokesman Chris Augustine said that the problem did not result in any collection of location records from cellphone towers.

According to the NSA's general counsel, Glenn S. Gerstell, the irregularities were caused by one or more providers who sent NSA data sets that also included some numbers of people the targets had not been in contact with. When the agency then fed those phone numbers back to the telecoms to get the "second hop" records, NSA acquired metadata of people with no connection to the approved targets.


Senator Ron Wyden, a longtime NSA critic who for years tried to get the Section 215 program disclosed, now blamed the providers instead of NSA for the technical problems: "Telecom companies hold vast amounts of private data on Americans," Wyden said. "This incident shows these companies acted with unacceptable carelessness, and failed to comply with the law when they shared customers’ sensitive data with the government."

Former assistant attorney general for national security David Kris said that these "errors illustrated how new problems can sometimes crop up when the government makes systems more complex in an effort to better balance security and privacy."


Speculations

In the public statement it is said that the massive metadata deletion follows from the NSA's "core values of respect for the law, accountability, integrity, and transparency" but outsiders speculated about other motives: were these records destroyed before the Trump administration could misuse them? President Trump also tweeted about this issue and saw it as part of the "Witch Hunt" against him:


David Kris, former assistant attorney general for national security, replied to Trump that "This NSA program is only for international terrorism, not spying or clandestine intelligence activity, so unless your collusion included terrorism, it should be no problem for you personally!"



Links and sources
- TheMarketsWork.com: A Strange & Unsettling Day (2018)
- NYTimes.com: N.S.A. Purges Hundreds of Millions of Call and Text Records (2018)
- Emptywheel.net: AT&T Pulled Cell Location for its "Mobility Cell Data" (2015)
- HuffingtonPost.com: The NSA’s Telephone Metadata Program Is Unconstitutional (2014)

February 14, 2018

The hotlines between North and South Korea

(Updated: April 22, 2018)

The current 2018 Winter Olympics, held in PyeongChang, South Korea, led to a charm offensive by neighbouring North Korea, which included the reopening of a border hotline with the South, that had been closed for almost two years.

The reopening came with new photos of the fancy-looking communications equipment, which will be described here, as well as the fact that there's not just one phone line, but over 40. Unlike other hotlines, the ones between North and South Korea are mostly used for low-level practical issues.




A South Korean liaison officer speaks with his North Korean counterpart over the
inter-Korean communications channel at Panmunjom, January 3, 2018
(photo: Unification Ministry - click to enlarge)


The Red Cross hotline

The first hotline between North and South Korea became operational on September 22, 1971. The link was the result of the first inter-Korean Red Cross meeting held on September 20, which resulted in an agreement to establish two lines for direct telephone calls between the two countries.

It was also agreed to construct a liaison office inside the Joint Security Area (JSA) of Panmunjom, which is in the heavily-fortified Demilitarized Zone (DMZ). The direct telephone link between the liaison offices is therefore often called the Red Cross or border hotline.


Equipment of the hotline

On the South Korean side, the hotline equipment is located in the communication office on the second floor of the Freedom House, which was built in 1998. On the North side, the line ends at a desk in the Panmungak building, which is less than 100 meters (328 feet) away. In the Panmunjom area, the hotlines connect the inter-Liaison Office, the inter-Korean Red Cross Talks Liaison Office and the Front Office of the inter-Korean Talks Headquarters.

The current equipment, which is seen in the most recent photos, was installed in 2009 and consists of a large, wood-panelled console on a desk. On top is a sign that says "South-North Direct Telephone". The system features two disk drives, two sets of USB ports and one computer screen, which shows the Windows XP user interface. It's not clear what the function of the screen is, as there's no keyboard visible.



Equipment of the Red Cross or border hotline on the South Korean side
(photo: YTN News - click to enlarge)


Update: As noted on Twitter, the computer screen appears to show the user interface of a VoIP softphone client, maybe an ancient version of X-Lite, but that hasn't been confirmed yet. Probably this setup made it easier to have the calls recorded, for example by using the CD-stations.


Most important parts are however two telephone handsets, one red and one green. The red one is for incoming calls from North Korea, while the South uses the green handset to make outgoing calls to the North. However, both phone sets are capable of sending and receiving, but there have been installed two of them just in case one fails.

Since 2015, the console has two digital clocks on top, as in that year North Korea shifted to UTC+08:30 or Pyongyang Time (PYT), while South Korea stayed in the UTC+09:00 or Korea Standard Time (KST) zone. In the photo below, the green clock shows 3:34 for South Korea and the orange/red one 3:04 for North-Korea.

At the left of the hotline console there's a Samsung SF 530 fax machine through which North Korea sometimes sends messages about topics that range from logistics to threats.




Operation of the hotline

The hotline phones at the Inter-Korean Red Cross Liaison Office and the Inter-Korean Liaison Office on the South side are operated by officials from the Unification Ministry. They are experts in diplomatic protocol and have in the past played roles in face-to-face talks as well.

To resolve the problem of who calls first, it was decided that the South calls the North on odd dates, while on even dates it's the other way around. The daily routine for weekdays is that communication officials make a phone call everyday at 9:00 AM and again at 4:00 PM. No routine calls are made on Monday morning, Saturdays and Sundays and on bilateral holidays, except for when there are special requests.

The government can instruct to use the hotline for the exchange of official messages, which come in the form of a 'telephone notice' which means that a liaison officer calls the other side and reads a document carrying a proposal or official position on a proposal of the other side. All this is very similar to how the hotline between Washington and Moscow is operated, although that one is just for written communications.

Finally, when a document with official seals has to be delivered to either North or South Korea, a call is made to arrange a face-to-face meeting at a certain time on the demarcation line.


Earlier hotline equipment

The earlier equipment that was used on the hotline of inter-Korean Liaison Office can be seen in a series of photos published on the occasion of its reopening on August 14, 2000, after having been closed since November 1996:



South Korean minister of Unification, Park Jae-kyu using the hotline, August 14, 2000
(photo: The Korea Times - click to enlarge)



The South Korean minister of Unification using the hotline, August 14, 2000
(photo: eHistory - click to enlarge)


This earlier hotline device, with the size of a small refrigerator, has two telephone handsets, one in yellow and one in some kind of light green. In the upper section there's a tape recorder for each of the phone lines. It seems that after the new equipment was installed in 2009, the old device was kept as a remembrance, covered by a blue cloth with a golden fringe:



The old (left) and the new (right) hotline equipment
(photo: Unification News - click to enlarge)



More hotlines between the Koreas

After the Red Cross border hotline at Panmunjom was established, more lines would follow. On April 29, 1972, a direct line between Seoul and Pyongyang was secretly set up to prepare the visit of high-ranking officials to Pyongyang. Following this visit, the director of the CIA contacted North Korean president Kim Il-sung and they agreed upon a direct telephone line for the Inter-Korean Control Committee.

There are no reports about a phone line that connects the presidents of North and South Korea, like for example the famous Washington-Moscow Hotline, or the hotlines between the American president and several other heads of government. (See Update!)




The Joint Security Area (JSA) between North en South Korea, with the
North Korean Panmungak building, seen from the South
(photo: iStock - click to enlarge)


33 hotlines through Panmunjom

More lines were established throughout the 1990s and 2000s and since December 2010 there are 33 direct phone lines which connect North and South Korea through Panmunjom. Five of them are intended for daily communications, 21 for negotiations between the two countries, two for handling air traffic, two for sea transport and three for economic co-operation:

- 2 lines in Panmunjom for the Red Cross, since September 22, 1971.

- 1 line between Seoul and Pyongyang to prepare a high-level visit, since April 29, 1972.

- 20 lines between Seoul and Pyongyang for inter-Korean Red Cross talks, including 2 lines for the Central Red Cross Organisation, since August 18, 1972.

- 1 line between Seoul and Pyongyang for economic talks, since December 20, 1984.

- 2 lines between the newly established inter-Korean Liaison Office in the Panmunjom Freedom House and the Panmokgak building for inter-agency business talks, since May 18, 1992.

- 2 lines between Daegu (since September 18, 2001: Incheon) and Pyongyang for air traffic control, since November 19, 1997.

- 2 lines between Seoul and Pyongyang for the inter-Korean Maritime Authority, since August 12, 2005.

- 3 lines between Seoul and the Kaesong Industrial Complex for the inter-Korean Economic Cooperation Consultation Office, since November 1, 2005.

Several of these direct phone lines through Panmunjom have lost their original function, such as the one for economic talks, but these lines are now for example used as a fax line for communications between the North and South Korean Red Cross Liaison Office, which was opened on April 11, 2004.


The Joint Security Area (JSA) between North en South Korea, with
the new South Korean Freedom House, seen from the North
(photo: jaytindall.asia - click to enlarge)


15 hotlines outside Panmunjom

There are also 15 inter-Korean direct telephone lines which, due to geographical reasons, are not connected to Panmunjom:

- 3 lines between military authorities for the Donghae Bukbu Line, since December 5, 2003 (ultimately terminated in October 2010)

- 6 lines between military authorities for the Gyeongui Line, since August 15, 2005.

- 6 lines between Dorasan Station in the South and Panmun Station in the North for the inter-Korean railroad, since May 14, 2007.


Military hotlines

Besides the aforementioned telephone ines, there are also several military hotlines. In accordance with bilateral agreements, a West Sea communications link was established in September 2002 and an East Sea link in December 2003, each consisting of a phone line, a reserve phone line and a fax line (these lines may well be identical with those for the Gyeongui and the Donghae Bukbu railroads respectively).

Another military hotline was agreed upon in June 2004, in a step towards easing tensions and avoid accidental clashes. On the internet there are at least two photos that apparently show military hotlines between North and South Korea. We see ordinary military field telephones, which don't seem to have encryption capability, but it's possible that they are connected to separate encryption units:



South Korean Lieutenant Choi Don-Rim (left) communicates with a North Korean officer
at a military office near the Demilitarized Zone (DMZ) in 2005.
(photo: AFP - click to enlarge)



A South Korean military official communicates with his North Korean
counterpart through a military hotline, September 6, 2013.
(photo: Yonhap - click to enlarge)



Interruptions of the hotlines

Since the establisment of the first hotline in 1971, the direct communication links between North and South Korea were interrupted seven times, each time by North Korea:

1976:
On August 30, shortly after the Panmunjom ax attack, the hotline was shut down by the North. It was resumed on February 7, 1980 following a first working-level agreement to discuss the inter-Korean prime ministerial talks.

1980:
North Korea unilaterally declared to cease contact on September 24. The hotline was reopened again on September 29, following an agreement with the North Korean Red Cross for consultation on North Korean flood assistance.

1996:
The direct phone lines were aborted immediately after a North Korean submarine ran aground near Gangneung in the South in an attempted infiltration mission. Communications resumed on August 14, 2000 following the first agreement on inter-Korean ministerial talks.

2008:
North Korea declared the hotline "disconnected" after Seoul proposed a resolution about human rights in North Korea during the General Assembly of the United Nations in November. Communications resumed on August 25, 2009 with the visit of President Kim Dae-jung's special envoy to Seoul and inter-Korean Red Cross talks.

2010:
After the Cheonan incident, North Korea shut down all communications channels with the South on May 26. The air control phone line was re-established on October 18, 2010, while the lines at the inter-Korean Red Cross liaison office were reconnected on January 12, 2011.

2013:
On March 11, North Korea had stopped responding to calls on the Red Cross hotlines and also shut down the communication line with the American military command in South Korea, as well as the military telephone and fax lines used to coordinate cross-border travel to the joint industrial park in Kaesong. The North connected the Red Cross hotline again on June 7. A hotline used by military officials regarding travels to Kaesong was restored on September 6, 2013.

2016:
In February, Pyongyang stopped responding to South Korea's calls in the Panmunjom office after Seoul suspended a joint economic project at the Kaesong Industrial Complex over Pyongyang's nuclear tests. The military West Sea hotline was also closed, just like all other hotlines through Panmunjom, except for the two air traffic controle lines.


Most recent reopening

On January 3, 2018, North Korean leader Kim Jong Un gave the order to reopen the Panmunjom border hotline at 3:00 PM local time. According to South Korea's Unification Ministry, the North Koreans made first contact at exactly the time ordered.

Both sides were on the phone from 3:30 PM to 3:50 PM local time and during this initial 20-minute conversation, the two nations "checked technical issues of the communication line," according to a statement from South Korea's Unification Ministry.

The Ministry said North Korea phoned for a second time several hours later, suggesting the two sides wrap up business for the day. Other than checking that the link was operational, it is unclear what was discussed. According to a ministry spokeswoman there was no mention of future talks or the Olympics.

 
Update

A top-level telephone hotline between the presidents of North and South Korea was established on April 20, 2018, in preparation of a summit between both leaders later that month in the border town of Panmunjum. Before this meeting, both presidents are expected to have a talk over the phone, but no date has been set for the call.

According to the Yonhap news agency, the new hotline connects the desk of South Korean president Moon Jae-in at the presidential Blue House with North Korea's State Affairs Commission, which is headed by Kim Jong-un. South Korean officials were the first to pick up the phone, then took a return call from their North Korean counterparts to make sure the line was working in both directions.



A South Korean official talks on a phone for testing the new hotline
at the presidential Blue House in Seoul, April 20, 2018
(photo: Yonhap - click to enlarge)



A telephone set that is used for the hotline between
the presidents of North and South Korea
(photo: AFP - click to enlarge)


Links and sources
- Reuters: Unique 'hotline' sets stage for new North and South Korea talks (2018)
- Korea Exposé: Call Me Maybe: How N. and S. Korea Actually Communicate (2017)
- Huffington Post Korea: 남북 직통전화 개설과 중단의 간략한 역사 (2014)
- Ministry of Unification: 남북관계 지식사전