# CoNTe: A Core Network Temporal Blockchain for 5G
## 3 Federated Byzantine Agreement Consensus  
A consensus model must be deployed that functions in this mode of operation to make a blockchain that is temporal. The following section details how the Conte blockchain maintains safety, while removing currency and contract mechanics from its design. When compared to permissionless consensus models, such as Bitcoins Proof-of-Work (POW), classic Byzantine Fault Tolerant (BFT) algorithms have been favored for permissioned or consortia deployments due to its lower resource consumption achieved in exchange for a reduced and adjustable fault tolerance, commonly set as low as 20% for environments consisting of known peers [13]. However, BFT models, in turn, carry risk in lacking the standardization and interworking required of heterogeneous network deployment. A more recent approach extended for this research is the FBA model, which balances the permissionless decentralization of POW, with the lowered resource use of BFT consensus. Conte handles consensus while using a modified implementation of the Federated Byzantine Agreements (FBA) structure first introduced with the Stellar Consensus Protocol [14]. FBA functions by dividing networks into smaller clusters of interlinked consensus, aptly named'slices'. Partitioning the network into slices in this manner allows for deploying BFT agreements at internet scale, while making the trade-off of slower consensus speed. Functionally, these slices behave in a manner similar to network subnetting, eliminating traffic storms formed during broadcast consensus in existing Byzantine Fault Tolerant (BFT) algorithms and, at a macro level, allows for consensus to mirror the unbounded peer-wise model of backbone internet, with nodes spanning consensus slices, functioning as gateway. Modern blockchain consensus algorithms are characterized on the three matrices of safety, liveliness, and fault-tolerance. The FLP Impossibility Theorem states that any asynchronous consensus mechanism can only guarantee and choose two among the three [27]. Extending from this, FBA diverges from Classic BFT consensus in being asynchronous and, consequently, foregoes guarantees of fault tolerance. An example BFT consensus algorithm guaranteeing 25% fault tolerance uses an n \(\geq\) 3\(f\) + 1 security model, with total nodes \(N\), faulty nodes \(f\)\(\in\)\(N\), and n = {x\(\in\)\(N\)\(\mid\) x\(\
otin\)\(f\)}. For such  
Figure 1: A logical representation of 5G network functions, with a single function (AUSF) being decentralized by using Conte blockchain storage. a guarantee to function, classic BFT algorithms must, at minimum, operate in partial-synchrony, often using a global stabilization time (GST) to end voting, and with a known registry of nodes \(N\) in order to reliably identify \(f\) nodes at a given time \(T\)[28; 29]. Through choosing safety and liveness over fault tolerance in its core algorithm, Conte does not need to restrict participation or incentivize behavior among unmanaged nodes in order to reach agreement. In this manner, it functions in a manner mirroring internet backbone peering; where connectivity is piecemeal, extending unbounded in all directions, and changing in time-based on trust relationships not managed by the blockchain itself. In this structure, Conte offers an ideal starting point, allowing for blockchain connectivity to be locally managed under existing infrastructure paradigms (as temporal virtualized network functions), while safely settling and distributing finalized blocks among unmanaged and heterogeneous networks. For this research, we define safety and liveliness as:  
* Safety: nodes operating a Conte blockchain enjoy safety if node outputs are consistent, with no two nodes committing a conflicting values for the same block. * Liveness: nodes operating a Conte blockchain enjoy liveliness if they are able to reach consensus on new blocks without the participation of failed or malicious nodes. Replacing Fault Tolerance with Network QuorumConsensus in FBA's operates on a structure known as a quorum slice.