Resiliency and Survivability

Due to its nature as a platform, Dynex is expected to support long-term contracts for at least the lifetime of an average person. Despite this, even young smart contract platforms are experiencing performance degradation and inability to adapt to external conditions. Therefore, a cryptocurrency will depend on a small group of developers to provide a hard-fork to fix this problem, or else it will not be able to survive. As an example, the Ethereum network has been using the Proof-of-Work consensus algorithm and promises to switch to Proof-of-Stake in the near future. Nevertheless, delays in Proof-of-Stake development have resulted in several fixing hard forks and the community is still reliant on the core developers to implement the next hard fork.

The first common survivability issue is that developers often implement ad-hoc solutions in pursuit of popularity without conducting adequate research and testing. Inevitably, such solutions will result in bugs, which will in turn lead to hasty bug fixes, which will then lead to bug fixes of those bug fixes, etc., making the network unreliable and even less secure. Rather than seeking short-term innovation, Dynex focuses on using stable, well-tested solutions. Many of the solutions used in Dynex have been formalized in papers that have been presented at peer-reviewed conferences and have been widely discussed in the community.

Decentralization (and thus survivability) is also challenged by the absence of secure trustless light clients. Dynex aims to solve this problem without creating new ones. Since Dynex is a Proof-of-Work blockchain, a small header can easily be extracted from the block content. This header alone allows for the validation of the work done on it, and a headers chain is sufficient to select the optimal chain for synchronization with the network. Headers-chains, although much smaller than the full blockchain, still grow linearly over time. Recent research on light clients has demonstrated a way for light clients to synchronize with the network by downloading an even smaller amount of data, thus enabling untrusted low-end devices, such as mobile phones, to join the network. Dynex uses an authenticated state and allows clients to download proofs of the correctness of transactions included in a block. In this way, Dynex is accessible to anyone using a mobile phone, regardless of the blockchain size.

There is also a third potential problem, namely that while light clients solve the problem for Dynex users, they still do not solve it for Dynex miners, who must still keep the entire state for efficient transaction validation. Currently, blockchain systems allow users to store arbitrary data in this state. Due to the fact that this data lasts forever, it creates a lot of dust, which grows in size infinitely over time. In situations where the state is too large for random-access memory, an adversary may be able to generate transactions that are very slow to validate as they require random access to the miner’s storage. As a result, DoS attacks such as the one that occurred on Ethereum in 2016 may occur. The community’s fear of such attacks as well as the problem of “state bloat” without compensation for miners and users may have prevented scaling solutions from being implemented (such as larger block sizes, for instance). For this reason, Dynex contains a storage rent component: if an output remains in the state for four years without being moved, a miner may charge a small fee per byte.

Similarly to regular cloud storage services, this concept has only recently been proposed for cryptocurrencies and has several important implications. In the first place, it ensures that Dynex mining will always be stable, as opposed to Bitcoin and other proof-of-work currencies, where mining may become unstable once emission is completed56. Second, the growth of the state’s size becomes predictable and controllable, so Dynex miners are able to manage their hardware requirements more effectively. Finally, by collecting storage fees from outdated boxes, miners can return coins to circulation, thus preventing the steady decrease of circulating supply due to lost keys57. It is expected that all of these factors will support Dynex’s long-term viability, both technically and economically.

Reference: “Crypto Note v 2.0”; unknown author under the pseudonym Nicolas van Saberhagen; 2013