ByLock

ByLock was a smartphone application that allowed users to communicate via a private, encrypted connection. It was launched in March 2014 on Google Play, Apple App Store The app was downloaded over 600,000 times from its launch in April 2014 until March 2016, when it was permanently shut down. The Turkish National Intelligence Organization (Turkish: Millî İstihbarat Teşkilatı, MİT) stated that the app was downloaded mainly in Turkey and ByLock users were as “Fetullahist Terror Organisation (Feto) which was formerly known as “Gülen movement” members.

According to the security certificate inside the software, the author of the application is David Keynes. In an interview with Hürriyet Daily News, Keynes stated that the developer of ByLock was a former roommate (Keynes,Atalay Candelen and Ass. Prof. Dr. Mehmet Karabayir lived in Beaverton) of his, who had used Keynes' credit card to publish the app on the Apple App Store. Keynes also said that ByLock had not been available since January 2016.

ByLock was written by Atalay Candelen a.k.a. "Fox", Portland State University Computer Science graduate, and his business partner 4th grade police chief Veli Ozdemir. After July 15th Gulen movement coup attempt, Atalay Candelen first escaped to the United States then Europe. Atalay Candelen owns a business company in Poland and thus received residence permit from Polish government. Nowadays he lives in Germany, close to Polish border.Atalay Candelen's company designs and updates web pages of some of Germany's biggest brothels which Turks owned. Atalay Candelen is wanted  on the yellow list of terrorists by Turkish Ministry of Interior. The other ByLock software developer ex-cop Veli Ozdemir, interestingly, there is no arrest warrant against him, only an Istanbul prosecutor's office investigation that was opened in 2014. He lives in Totowa New Jersey, United States of America. Veli Ozdemir's company( Zenith Trade) sells water which brings from Turkey to the USA.

Before the December 17/25 events, the police wing of the FETO organization decided to establish its own communication channel, as they believed that all other communication channels would be monitored by the state government afterward. In the first week of December 2013, high-level FETO members, who were police officers working in the Intelligence Department in Ankara's Yıldız district, organized a meeting with Atalay Candelen, who owns an IT company, and his partner, Veli Ozdemir, a former police chief. The first version of the program, known as SHU, was developed by Atalay Candelen and his team in their office at the Technopark (Istanbul University) and was implemented by members of an organization on December 29, 2013. The first version of the Bylock program was not placed on Google Play or the Apple App Store. It was downloaded by members of the organization using Bluetooth and computers, etc. Because the Apple Store did not allow the backdoor (spyware) in the first version of Bylock (SHU), the program was rewritten and renamed as ByLock, and it was added to Google Play and the Apple Store in March and April 2014, respectively. In July 2014, in a parallel state operation, police officers who were members of the Feto terrorist organization were detained. Turkish law enforcement became aware of the program when the Bylock program was found on the phones and iPads of the Feto police officers. FETO's police wing decided to spread ByLock to all its members to confuse the Turkish law enforcement forces and make them devote all their energy to it, and then stopped using the program. Since there was a lot of time for the organization leader Fethullah Gülen's quarterly meeting with the organization's executive board, Atalay Candelen obtained permission from Fethullah Gulen through Cevdet TURKYOLU, his future brother-in-law, for all members of the organization to use the program. On August 8th, 2014, ByLock was transferred from a server in Germany to a server in Lithuania by the order of Cevdet TURKYOLU.