Meet Africa’s Blockchain Startups: Custos Media Technologies


South Africa-based Custos Media Technologies aims to fight online media piracy using blockchain technology. Founded in 2014 at the New Media Research Lab in Stellenbosch, the startup is run by a team of experienced specialists in disciplines such as cryptocurrency, signal processing, machine learning and media economics. Since its inception, the company has been working towards creating a watermarking technology that combats piracy using the bitcoin blockchain.

Custos’ CEO G-J Van Rooyen is an Electronic Engineering Ph.D. holder who majors in the commercial application of the blockchain. Custos Technologies aims to help film makers and other content creators to ‘eradicate piracy’ in a smart manner. They identify the specific people responsible for illegally leaking files using a trace back technique. 

How It Works

Custos Media TechnologiesCustos embeds a reward on target files. It utilises the ‘bounty hunter’ method, where individuals who find pirated files are rewarded for finding new infringements. The company embeds bitcoin rewards on the copies sent out to recipients. This lures anonymous bounty hunters to claim the prize, and this way, Custos can instantly detect the leak. The company then trails back to the person who initiated the leak, and then informs their client about who the original pirate is.

The targets comprise of three groups. The first group consists of the bounty hunters, who are basically anonymous users in piracy communities. To get a large number of users, Custos makes pieces of free software. In most cases, these bounty hunters use the Custos’ tools for personal gains. The company notes that humans are ‘endlessly resourceful in finding things’ especially when there’s a reward for it.

These hunters allow Custos’ software to crawl into the dark web, deep web or anywhere else where ordinary content crawlers have no opportunity to scour. The fact that the bounty hunters remain anonymous makes the deal even more lucrative for them.

The second group consists of Custos’ trusted partners who offer web crawling services. The crawlers search and identify the Custos protected files. Then, the third group is made of Custos’ forensic team. The team utilises web algorithms to find pirated content. Once the client is informed, it is up to them to deal with the source of the leak.

According to Van Rooyen, a bounty on contraband eBook or film or any other content takes less than five minutes to be claimed. On leading social networks, it can take about 42 seconds for the reward to be claimed. Rooyen says that Custos is also able to detect content shared offline. He adds that it takes 28 minutes to identify a movie or file shared on a DVD or USB drive.

Early Success

Despite all the hype, Von Rooyen indicates that the project is still in its ‘very early stages’. Yet, Rooyen says that Custos has been able to catch a good number pirates. He says that the majority of its bounty hunters are college students from developing countries who take the $5-$10 worth of bitcoin reward seriously.

Regarding the use of bitcoin, Rooyen explains that Custos relies on several anonymous users who have the information needed by clients and bitcoin, he believes, is an ideal way to pay them anonymously. 

Tags : Custos Media Technologiessouth africa
Kinyua Njeri

The author Kinyua Njeri

Kinyua is a Kenyan freelance writer who focuses on technology. Kinyua’s motto is ‘Research deeply, Test thoroughly, and Write simply’. His work has appeared on Cyberogism,, and in The Nairobi Times.