We present a decentralised alternative to the winner-takes-everything dynamics of social media platforms.

For 25 years there have been continuous attempts to decentralise file sharing, music streaming, video conferencing, and social media. 

None of these hundreds of projects to re-decentralise the Internet have reached the uptake level of YouTube and TikTok. They are rarely easy to use.

We present DeToks, a fully decentralised alternative to Youtube and Tiktok. DeToks is not dependant on any central server or cloud. DeToks is specifically designed to be as decentralised and attack-resilient as Bitcoin and Bittorrent.

Our core contribution is effortless 5G Network Address Translators (NATs) puncturing.

Direct phone-to-phone communication is not available on today's smartphones. DeToks solves this problem.

NATs and carrier-grade NATs block direct communication between smartphones. 

We procured 30+ SIMs card on European 4G/5G mobile networks and measured the carrier-grade NATs behavior. We determined the NAT types (full cone,restricted,symmetric) and their time-out settings. By leveraging provider-aware (Vodafone,Orange,Telia, etc.) NAT puncturing strategies we create direct UDP-based phone-to-phone connectivity. 

We utilise parallelism by opening at least 500 Internet datagram sockets on two devices. By relying on provider-aware IPv4 range allocations, provider-aware port prediction heuristics, high bandwidth probing, and the birthday paradox we can successfully bypass even symmetric NATs. Our communication method achieves peer-to-peer 5G connectivity at the cost of merely some initial delay and bandwidth, without any assistance from third party servers or clouds.

Detoks validates our 5G puncturing work. We demonstrate the feasibility of fully decentralized social media platforms on consumer mobile devices.

The rise in the use of crowd computing platforms led to the birth of Dandelion, a conversational crowd computing platform developed at TU Delft with the main goals being to connect students with researchers and to allow students to report on their well-being by using a friendly interface. Dandelion was tested manually up to the time of drafting this paper; thus, the primary motivation behind this paper is to ensure the robustness and measure the responsiveness of Dandelion.

Robustness was exercised by utilizing a simulated user behaving unexpectedly. The testing framework then classifies the behaviour of Dandelion according to the C.R.A.S.H. scale. The testing framework is validated by altering Dandelion's behaviour and ensuring that the test results reflect the change. Furthermore, a lower bound to the run time of a task will be estimated using a Multi-Agent System (M.A.S.) simulation on Dandelion.

Upon verifying the correctness of the robustness test, a faulty assumption was uncovered on which the user's input validation was based. Furthermore, the M.A.S. simulation run estimated a lower bound of $\approx 5.788$ seconds, while revealing a lack of user's input validation before posting them in the database.