BACKGROUND

Recent years have seen significant advancements in hardware and software platforms for managing distributed ledger databases across a network of computing devices. Indeed, so-called “blockchain” systems can manage a consensus ledger via a network of entities distributed throughout the world and without a central entity that can be corrupted or otherwise manipulated to undermine the security and performance of the digital ledger. Specifically, conventional blockchain systems can decentralize control by maintaining a digital ledger on many replicated servers, or validator nodes. Algorithms, cryptography, and incentives enable such networks of validator nodes to maintain a collective, tamper-resistant ledger of transactions or other digital information.

Despite these advances, however, conventional blockchain systems suffer from several technological shortcomings that undermine efficiency, scalability, flexibility, and security of the implementing computing devices and corresponding distributed databases. For example, conventional blockchain systems often require significant processing and storage for validator nodes and client devices that interact across the implementing network. As mentioned above, many conventional blockchain systems maintain a duplicate database across replicated servers that store a history of digital transactions. Moreover, many conventional blockchain systems sequentially analyze transactions across the validator nodes to achieve consensus on the transactions and ultimately to update the distributed and duplicated ledger. This approach can place exorbitant storage and processing demands on computing devices. Indeed, the demand for certain processing devices has skyrocketed in recent years in proportion to the increased computing demand required by conventional blockchain systems in storing and analyzing transactions across distributed computer networks.

The inefficiencies of conventional blockchain systems have also hampered the scalability of these systems. For example, processing and storage burdens imposed by conventional blockchain systems undermine transaction throughput across the network and thus limit the rate and number of transactions that conventional systems can manage. Accordingly, conventional blockchain systems generally lack the scalability to provide a global distributed computing solution for managing digital transactions. Indeed, to date, conventional blockchain systems have generally been limited to a small population of niche users, excluding billions from accessing and utilizing blockchain technology.

In addition to efficiency and scalability concerns, conventional blockchain systems are also rigid and inflexible. For example, conventional blockchain systems provide limited options with regard to different programs, transactions, contracts, assets, and/or resources that can be accommodated or executed via a distributed database. Moreover, conventional blockchain systems provide limited control for storage at validator nodes, limited flexibility in executing transactions at validator nodes, and limited options over authentication keys and validation approaches for account holders and users of client devices accessing the network.

As mentioned above, conventional blockchain systems are also susceptible to inaccuracies and/or digital security attacks. For example, groups of validator nodes can agree on different versions of digital ledgers, resulting in inaccuracies, hard-forks, and insecurity of the underlying digital information. Some conventional systems perform consensus on transaction blocks, assuming execution of the transactions will be deterministic; thus, any non-deterministic execution behavior can result in inaccurate results at individual devices (or inaccuracies propagated across the digital ledger). Further, many conventional systems utilize bloom filters when providing transaction details in response to a query, risking false positives and failing to provide the ability for negative proofs to confirm accuracy of account data. Further, conventional blockchain systems often provide unrestricted digital asset access to user accounts storing digital assets, leading to exposure of all assets to malicious attacks upon loss of a private key associated with a user account. Additionally, as many conventional systems perform reference safety analysis on source code while programs are executed at the machine code level, many such systems inaccurately identify reference safety issues and/or introduce vectors for malicious attacks.

These, along with additional problems and issues, exist with regard to conventional blockchain systems.

SUMMARY

One or more embodiments described herein provide benefits and/or solve one or more of the foregoing or other problems in the art with systems, methods, and non-transitory computer readable storage media for implementing a scalable, secure, efficient, and adaptable distributed digital ledger transaction network. Indeed, the disclosed systems can reduce storage and processing requirements, improve security of implementing computing devices and underlying digital assets, accommodate a wide variety of different digital programs (or “smart contracts”), and scale to accommodate billions of users and associated digital transactions.

For example, the disclosed systems can make data storage more scalable and efficient by treating the blockchain in consensus as a single data structure that records the history of transactions and states over time. This implementation simplifies the work of computing devices accessing the blockchain, allowing them to read data from any point in time and verify integrity using a unified framework. Similarly, to obtain agreement among validator nodes, the disclosed systems can utilize a unique Byzantine-fault-tolerant consensus protocol. This approach provides high transaction throughput, low latency, and a more computationally-efficient method for achieving consensus relative to other blockchains.

In addition, the disclosed systems can utilize a new programming language to implement smart contracts on the blockchain. In particular, this new programming language makes it inherently easier to write code to fulfill user intent, thereby avoiding unintended bugs or security incidents (e.g., preventing asset cloning). Specifically, the disclosed systems can utilize a programming language that enables a linear data type that constrains digital assets to properties of a physical asset (e.g., a single owner, can only be spent once, restrictions against creation of new resources). In some embodiments, the disclosed systems also utilize an implementing programming language having a tree structure memory model for improved reference safety analysis. Using this programming language, the disclosed systems can implement a static-dynamic reference safety analysis at the bytecode level, reducing vectors for malicious attacks.

Furthermore, the disclosed systems provide a host of additional features that improve storage, account/address management, digital transaction execution, consensus, and synchronization processes. For example, with regard to storage, the disclosed systems can implement flexible storage deletion and/or storage consolidation policies that allow individual computer nodes to delete distributed data structures while retaining sufficient ledger information to accurately achieve consensus across the distributed digital ledger transaction network. The disclosed systems can also implement lazy account eviction policies that allow for more flexible storage management based on the individual preferences and/or the availability of computer memory or processing power at individual computing devices. The disclosed systems can also utilize a unique scratch pad data structure that flexibly tracks variations of the digital ledger while waiting for consensus.

Similarly, the disclosed systems can provide a variety of improvements with regard to user accounts, addresses, and account data accessible on a digital ledger. To illustrate, the disclosed systems can utilize re-encrypted sub-addresses to avoid tracing of account activity across the network. The disclosed systems can reduce barriers to initiate transactions by utilizing e-mail addresses (or other user identifiers) to determine and encrypt main address and sub-address identifiers corresponding to the distributed ledger. In addition, the disclosed systems can separate smart contract code from smart contract data within user accounts, allow individual accounts to store multiple smart contracts, delegate account permissions to other user accounts on the digital ledger, and decouple account addresses from cryptographic keys (allowing accounts to flexibly rotate authenticated keys to improve security across the network).

Furthermore, the disclosed systems can improve digital transactions executed across a distributed digital ledger transaction network. For example, the disclosed systems can implement transactions on the network using arbitrary transactions scripts and configurable smart contracts to manage tasks surrounding transaction execution. To illustrate, in some embodiments, the disclosed systems can utilize configurable smart contracts to accept/reject transactions, deduct gas payments, increment sequence numbers, and distribute gas to computer nodes (and flexibly modify these processes by consensus as needs of the distributed digital ledger transaction network change over time). In some embodiments, the disclosed systems further improve transaction execution by performing speculative parallel execution of transactions to reduce the time and computing overhead needed to execute a block of transactions, utilizing access limits to reduce exposure of digital assets resulting from theft or loss of an access key, and using transaction event counters to accurately identify transaction event details and perform negative proofs.

In addition to improvements in digital transaction execution, the disclosed systems can also improve consensus processes relative to conventional systems. For example, the disclosed systems can improve accuracy by performing consensus on state data structures reflecting execution results (rather than performing consensus on potentially non-deterministic transactions). The disclosed systems can also implement consensus pipeline rules to ensure that committed ledgers accurately reflect the state of the digital ledger. In some embodiments, the disclosed systems further implement system restart protocols to maintain consensus safety of the network (e.g., even when all nodes experience a shutdown). Moreover, the disclosed systems can efficiently, flexibly, and accurately control validator nodes participating in consensus by managing epochs of voting rights via smart contracts.

In addition to the foregoing improvements, the disclosed systems can also improve synchronization processes across the distributed digital ledger transaction network. For instance, the disclosed systems can improve the efficiency of synchronization across the distributed digital ledger transaction network by implementing incremental and parallel verification at various computer nodes synchronizing to the network. In addition, in some embodiments the disclosed systems utilize waypoints (e.g., published indicators of particular ground-truth reference states) to facilitate synchronization of computer nodes to the network (e.g., to correct conflicting digital ledger states, to generate a hard fork, or implement a genesis block).

In sum, the disclosed systems can implement a distributed digital ledger transaction network with high transaction throughput, low latency, and an efficient, high-capacity storage system. Moreover, the disclosed systems can securely manage a wide variety of digital assets, flexibly accommodate a variety of different customizable programs and smart contracts, and scale to execute and manage digital transactions for users across the globe.

