ドージコイン：コミュニティ主導の暗号通貨

Abstract

Dogecoin is a decentralized, peer-to-peer cryptocurrency that was forked from Litecoin in December 2013. Originally created as a lighthearted alternative to Bitcoin, Dogecoin has grown into a widely used digital currency with a vibrant community. Built on the Scrypt proof-of-work algorithm, Dogecoin features fast block times, low transaction fees, and an inflationary monetary policy designed to encourage spending and tipping rather than hoarding.

Unlike most cryptocurrencies that position themselves as stores of value or financial infrastructure, Dogecoin was conceived with an emphasis on accessibility, generosity, and fun. Its low barrier to entry and welcoming community have made it one of the most widely held cryptocurrencies in the world. This document describes the technical foundations, monetary policy, network architecture, and development history of Dogecoin, providing a comprehensive reference for a cryptocurrency that, despite its humorous origins, operates on robust and well-tested cryptographic principles inherited from Bitcoin and Litecoin.

Introduction

On December 6, 2013, software engineers Billy Markus and Jackson Palmer launched Dogecoin, a cryptocurrency inspired by the popular "Doge" internet meme featuring a Shiba Inu dog. What began as a joke aimed at satirizing the rapid proliferation of alternative cryptocurrencies quickly evolved into a legitimate digital currency with a passionate global community. Within the first month of its existence, Dogecoin's website received over a million visitors, and its community began organizing charitable fundraising campaigns that would become a hallmark of the project.

Dogecoin was created by forking the Litecoin codebase, which itself was a fork of Bitcoin. This lineage provided Dogecoin with a battle-tested foundation of cryptographic security and decentralized consensus. However, Markus and Palmer made deliberate design choices that differentiated Dogecoin from its predecessors: faster block generation times, a more abundant coin supply, and a friendly, approachable brand identity that stood in stark contrast to the often technical and exclusionary culture surrounding other cryptocurrencies.

The cryptocurrency landscape in late 2013 was characterized by a Bitcoin price surge and an explosion of alternative coins, many of which made grandiose claims about revolutionizing finance. Dogecoin entered this environment as a self-aware counterpoint, embracing absurdity while delivering genuine utility. Its low per-unit cost made it psychologically accessible to newcomers, and its fast confirmation times made it practical for small, everyday transactions. The Dogecoin community quickly adopted a culture of tipping content creators on social media platforms and pooling funds for charitable causes, establishing use patterns that distinguished it from the speculation-driven culture of many other cryptocurrencies.

Despite its unconventional origins, Dogecoin has demonstrated remarkable longevity and resilience. It has maintained continuous network operation since its launch, undergone significant protocol upgrades, and consistently ranked among the top cryptocurrencies by market capitalization. Its survival and growth over more than a decade is a testament to the strength of its community and the soundness of the underlying technology inherited from the Bitcoin and Litecoin codebases.

Background

Dogecoin's technical foundation is rooted in two prior open-source cryptocurrency projects: Bitcoin and Litecoin. Understanding these predecessors is essential to understanding Dogecoin's architecture and design decisions.

Bitcoin, introduced in 2008 by the pseudonymous Satoshi Nakamoto, established the fundamental paradigm for decentralized digital currencies. It demonstrated that a peer-to-peer network could achieve consensus on the state of a shared ledger without requiring a trusted central authority. Bitcoin's proof-of-work mechanism, based on the SHA-256 hashing algorithm, provided a Sybil-resistant method for validating transactions and producing new blocks. However, Bitcoin's design prioritized security and decentralization, resulting in relatively slow block generation times of approximately ten minutes and a deflationary monetary policy with a hard cap of 21 million coins.

Litecoin, created by Charlie Lee in October 2011, was one of the earliest and most successful Bitcoin forks. Lee modified several of Bitcoin's parameters with the goal of creating a "lighter" version suitable for smaller, more frequent transactions. The most significant change was the adoption of the Scrypt hashing algorithm in place of SHA-256. Scrypt is a memory-hard function that was originally designed to make brute-force attacks on password hashes more expensive. By requiring significant memory in addition to computational power, Scrypt was intended to resist the advantage that specialized ASIC (Application-Specific Integrated Circuit) mining hardware held over general-purpose CPUs and GPUs. Litecoin also reduced block generation time to 2.5 minutes and increased the total coin supply to 84 million.

When Billy Markus set out to create Dogecoin in late 2013, he chose to fork the Luckycoin codebase, which was itself a fork of Litecoin. This decision inherited Litecoin's Scrypt-based proof-of-work, its UTXO (Unspent Transaction Output) transaction model, and its general network architecture. Markus then made additional modifications to further differentiate Dogecoin: the block time was reduced to one minute, the initial coin supply was dramatically increased, and a randomized block reward system was implemented for the early distribution phase. These changes were designed to create a cryptocurrency that was fun to mine, easy to acquire, and suitable for the microtransactions and tipping culture that the founders envisioned.

The decision to base Dogecoin on Scrypt rather than SHA-256 had important implications for its mining ecosystem. In 2013, Bitcoin mining had already become dominated by ASIC hardware, making it impractical for ordinary users to participate. Scrypt ASICs did not yet exist when Dogecoin launched, meaning that GPU mining was still viable and accessible. This leveled the playing field for early miners and contributed to the broad distribution of coins during Dogecoin's formative period.

Technical Specifications

Dogecoin operates on a proof-of-work consensus mechanism using the Scrypt hashing algorithm. Scrypt was chosen through its inheritance from Litecoin and provides a memory-hard proof-of-work function that requires both computational power and memory access, distinguishing it from Bitcoin's purely computation-intensive SHA-256 algorithm.

The block generation target for Dogecoin is one minute, making it significantly faster than both Bitcoin (ten minutes) and Litecoin (2.5 minutes). This rapid block time provides several practical advantages: transactions receive their first confirmation more quickly, reducing the wait time for merchants and users; the network can process a higher theoretical throughput of transactions per unit of time; and the mining reward distribution occurs more frequently, providing a smoother income stream for miners.

Each Dogecoin block has a maximum size of one megabyte, consistent with the original Bitcoin block size limit. Given the one-minute block time, this provides an effective throughput capacity roughly ten times that of Bitcoin's original design. In practice, Dogecoin blocks typically operate well below capacity, ensuring that transactions can be included in the next block with minimal fees.

The difficulty adjustment algorithm recalculates the mining difficulty every 240 blocks, which corresponds to approximately four hours at the target one-minute block time. This relatively frequent adjustment helps the network respond to changes in hash rate more quickly than Bitcoin, which adjusts every 2016 blocks (approximately two weeks). The faster adjustment period is necessary given Dogecoin's shorter block time and helps maintain a stable block production rate even as miners enter and leave the network.

Dogecoin uses the same UTXO (Unspent Transaction Output) model as Bitcoin for tracking ownership of coins. Each transaction consumes one or more UTXOs as inputs and creates new UTXOs as outputs. This model provides a transparent and auditable record of coin ownership without requiring account balances to be maintained in a global state. Transaction scripts use the same scripting language as Bitcoin, supporting standard transaction types including pay-to-public-key-hash (P2PKH) and script-hash">pay-to-script-hash (P2SH).

Addresses in Dogecoin begin with the letter "D" and are derived from ECDSA (Elliptic Curve Digital Signature Algorithm) public keys using the secp256k1 curve, the same elliptic curve used by Bitcoin. The address format includes a version byte specific to Dogecoin, a hash of the public key, and a checksum for error detection. This ensures that Dogecoin addresses are visually distinguishable from Bitcoin and Litecoin addresses, preventing accidental cross-chain transfers.

The network protocol operates on port 22556 for mainnet connections and port 44556 for testnet. Nodes communicate using a protocol derived from Bitcoin's peer-to-peer messaging system, with messages for block propagation, transaction relay, peer discovery, and network health monitoring. The protocol includes version handshaking to ensure compatibility between nodes running different software versions.

Monetary Policy

Dogecoin's monetary policy is one of its most distinctive features and represents a deliberate departure from the deflationary models adopted by Bitcoin and most other cryptocurrencies. Rather than imposing a hard cap on the total supply, Dogecoin features a perpetually inflationary issuance schedule that adds approximately 5.256 billion new coins to the supply each year.

During its initial distribution phase, Dogecoin employed a unique randomized block-reward/" class="glossary-link" data-slug="block-reward" title="block reward">block reward system. From blocks 1 through 99,999, the reward for mining a block was randomly determined between 0 and 1,000,000 DOGE. This randomness was intended to add an element of fun and unpredictability to the mining process, consistent with the project's lighthearted ethos. Miners could receive anything from zero to a million coins for finding a single block, creating a lottery-like dynamic that generated excitement in the early community.

The reward schedule was subsequently structured into halving periods. From block 100,000 through 144,999, rewards were randomized between 0 and 500,000 DOGE. Blocks 145,000 through 199,999 offered randomized rewards up to 250,000 DOGE, and blocks 200,000 through 299,999 offered up to 125,000 DOGE. At block 300,000, the randomization was removed, and a fixed reward of 62,500 DOGE per block was established. At block 600,000, the reward was halved to 31,250 DOGE. Finally, beginning at block 600,001, the block reward was permanently fixed at 10,000 DOGE per block, with no further halvings planned.

This permanent fixed reward of 10,000 DOGE per block means that approximately 14.4 million new coins are mined each day, totaling roughly 5.256 billion new coins per year. While this constitutes an inflationary policy in absolute terms, the inflation rate as a percentage of total supply decreases over time. As the total supply grows, each year's new issuance represents a smaller fraction of the whole. By the year 2025, with approximately 147 billion coins in circulation, the annual inflation rate had fallen below 3.6 percent, and it continues to decline asymptotically toward zero.

The designers of Dogecoin's monetary policy argued that a modest, predictable inflation rate serves several beneficial purposes. It incentivizes spending and circulation rather than hoarding, since holders face gradual dilution if they simply sit on their coins. It ensures that miners continue to receive meaningful block rewards in perpetuity, maintaining network security without requiring the network to rely solely on transaction fees as Bitcoin will eventually need to do. And it replaces coins that are inevitably lost due to forgotten passwords, hardware failures, and other causes of permanent inaccessibility, preventing the effective money supply from shrinking over time.

The total supply of Dogecoin surpassed 100 billion coins in mid-2015. By early 2026, approximately 148 billion DOGE exist. This large supply, combined with the relatively low per-unit price, gives Dogecoin a psychological advantage for use in tipping and microtransactions. Users can send whole-number amounts rather than dealing with the fractional quantities common in Bitcoin transactions, making the currency more intuitive for everyday use.

Network Architecture

The Dogecoin network consists of a distributed set of nodes that maintain a complete copy of the blockchain and validate all transactions and blocks according to the protocol's consensus rules. Like Bitcoin and Litecoin, Dogecoin uses a gossip-based peer-to-peer protocol for disseminating transactions and blocks across the network. When a node receives a new transaction or block, it validates it against the protocol rules and, if valid, relays it to its connected peers.

Full nodes form the backbone of the network. Each full node independently verifies every transaction and block from the genesis block forward, maintaining a complete and independently validated copy of the entire transaction history. This redundancy ensures that no single point of failure exists and that any participant can independently audit the integrity of the blockchain. Dogecoin Core, the reference implementation maintained by the Dogecoin development team, serves as the primary full node software.

Mining is the process by which new blocks are added to the blockchain and new DOGE coins are created. Miners compete to find a nonce value that, when combined with the block header data and processed through the Scrypt hashing algorithm, produces a hash value below the current difficulty-target/" class="glossary-link" data-slug="difficulty-target" title="difficulty target">difficulty target. The miner who finds a valid hash first broadcasts the new block to the network and claims the block reward of 10,000 DOGE plus any transaction fees included in the block.

One of the most significant changes in Dogecoin's history was the adoption of Auxiliary Proof of Work (AuxPoW), commonly known as merge mining, in August 2014 with the release of Dogecoin Core 1.8. Merge mining allows miners to simultaneously mine multiple cryptocurrencies that use the same hashing algorithm without any additional computational cost. In practice, this means that Litecoin miners can include Dogecoin block headers in their Litecoin mining work, effectively securing both chains with the same hash power.

The adoption of merge mining was motivated by a critical security concern. By mid-2014, dedicated Dogecoin mining had become economically marginal as the block reward halvings reduced miner revenue. The network's hash rate was declining, making it increasingly vulnerable to 51 percent attacks. By enabling merge mining with Litecoin, Dogecoin could benefit from Litecoin's substantially larger mining ecosystem. The result was a dramatic increase in Dogecoin's effective hash rate, as major Litecoin mining pools began merge-mining Dogecoin essentially for free. This made the network significantly more secure than its standalone economics could support.

Under the merge mining protocol, a Litecoin miner constructs a block that includes a reference to a Dogecoin block header in its coinbase transaction. If the Litecoin proof-of-work solution also satisfies Dogecoin's difficulty requirement, the miner can submit it to the Dogecoin network as a valid block. Since Litecoin's difficulty is typically much higher than Dogecoin's, most Litecoin blocks will also qualify as valid Dogecoin blocks. This means that Dogecoin effectively inherits the security of the Litecoin mining network.

The network's peer discovery mechanism uses a combination of DNS seeds and peer exchange. When a new node starts for the first time, it contacts hardcoded DNS seed nodes to obtain a list of active peers. Once connected to the network, nodes exchange peer addresses with their neighbors, gradually building a diverse and resilient set of connections. The protocol targets a default of eight outbound connections per node, though nodes can accept additional inbound connections.

Transaction propagation across the network is typically rapid, with most nodes receiving a new transaction within seconds of its initial broadcast. Block propagation is similarly fast, though the larger data size means it takes slightly longer to disseminate across the entire network. The one-minute block time means that transactions typically receive their first confirmation within one to two minutes of being broadcast, making Dogecoin practical for point-of-sale transactions where faster confirmation is desirable.

Use Cases and Community

Dogecoin's most distinctive characteristic, beyond its technical specifications, is the community that has formed around it. From its earliest days, the Dogecoin community established a culture centered on generosity, humor, and accessibility that has set it apart from virtually every other cryptocurrency project.

Tipping was one of Dogecoin's first and most prominent use cases. Within weeks of its launch, community members created bots for Reddit and Twitter that allowed users to tip each other in DOGE for creating entertaining or helpful content. The low per-unit cost of DOGE made tipping psychologically easy — sending someone 100 DOGE felt more impactful and fun than sending 0.00005 BTC, even if the dollar values were comparable. This tipping culture created a natural introduction to cryptocurrency for millions of people who might never have engaged with Bitcoin's more technical and financially oriented community.

The Dogecoin community organized several high-profile charitable campaigns that brought significant public attention to the project. In January 2014, the community raised approximately 27 million DOGE (valued at roughly $30,000 at the time) to help fund the Jamaican bobsled team's trip to the Winter Olympics in Sochi, Russia. This campaign captured widespread media attention and established Dogecoin's reputation as a force for positive action. The community subsequently raised funds for clean water projects in Kenya through the Doge4Water campaign, sponsored NASCAR driver Josh Wise in the Doge-themed car number 98, and contributed to numerous other charitable causes.

As a medium of exchange, Dogecoin's technical properties make it well-suited for microtransactions and casual payments. Transaction fees on the Dogecoin network are typically fractions of a cent, making it economically viable to send very small amounts. The one-minute block-time/" class="glossary-link" data-slug="block-time" title="block time">block time provides reasonably fast confirmation for in-person transactions. The large circulating supply means that most transactions can be denominated in whole numbers rather than the unwieldy decimal amounts required by Bitcoin, reducing cognitive friction for users.

Dogecoin has been adopted by a number of merchants and service providers as a payment method. Online retailers, gaming platforms, and content creators have integrated Dogecoin payments, attracted by the low transaction costs and the enthusiastic community of potential customers. Several cryptocurrency payment processors support Dogecoin, allowing merchants to accept DOGE and receive settlement in their local fiat currency if desired.

The project has also served an important educational role in the broader cryptocurrency ecosystem. Dogecoin's approachable branding and welcoming community have made it a common entry point for people learning about digital currencies, blockchain technology, and decentralized systems. Many cryptocurrency enthusiasts who went on to become deeply involved in other projects first encountered the technology through Dogecoin.

In 2021, Dogecoin experienced a dramatic surge in mainstream attention and market capitalization, driven in part by social media advocacy from prominent public figures. While this period of intense speculation was controversial within the community, it brought millions of new users to the Dogecoin network and cemented the coin's position as one of the most widely recognized cryptocurrencies in the world.

Development History

Dogecoin's development history reflects the evolution of a project that began as a quick weekend experiment and matured into a serious open-source cryptocurrency maintained by a dedicated team of volunteer developers.

The initial release of Dogecoin on December 6, 2013, was based on a fork of the Luckycoin codebase, which was itself derived from Litecoin. Billy Markus made modifications to customize the coin's parameters, including the block-reward/" class="glossary-link" data-slug="block-reward" title="block reward">block reward schedule, block time, and branding. The software was released as Dogecoin Core 1.0, and the genesis block was mined on December 6, 2013.

In the early months, development focused on stability and bug fixes. Dogecoin Core 1.1 through 1.4 addressed various issues as the network grew rapidly and the community expanded. A significant early crisis occurred when a vulnerability allowed a malicious fork of the chain, requiring an emergency patch and community coordination to resolve.

Version 1.5, released in early 2014, removed the randomized block reward system ahead of schedule. While the random rewards had been a fun and distinctive feature, they posed challenges for mining-pool/" class="glossary-link" data-slug="mining-pool" title="mining pool">mining pool operators and made revenue projections difficult for miners. The development team replaced the randomized rewards with a deterministic schedule, maintaining the same total issuance rate while making block rewards predictable.

The most consequential protocol upgrade in Dogecoin's history was the implementation of Auxiliary Proof of Work (AuxPoW) in version 1.8, released in September 2014. This change enabled merge mining with Litecoin and other Scrypt-based cryptocurrencies. The decision was driven by mounting security concerns as Dogecoin's standalone hash rate declined following the block reward halvings. The transition to AuxPoW required a hard fork of the network and represented a significant departure from Dogecoin's origins as a standalone chain. However, it proved to be the correct decision, as the merged mining arrangement dramatically increased the network's security.

Dogecoin Core 1.10, released in 2015, brought the codebase more closely in line with upstream Bitcoin Core changes, incorporating improvements to networking, validation, and wallet functionality. Subsequent releases continued this pattern of tracking Bitcoin Core improvements while maintaining Dogecoin-specific parameters and features.

After a period of slower development in the mid-2010s, the Dogecoin project was revitalized in the late 2010s with the formation of the Dogecoin Foundation in 2021. The Foundation brought renewed organizational structure and funding to the project, supporting ongoing development and community initiatives. A new generation of developers joined the project, working on modernizing the codebase, improving documentation, and planning future protocol enhancements.

Dogecoin Core 1.14.6, released in late 2022, introduced significant improvements to fee handling, including a reduction in the default minimum relay fee. This change made Dogecoin transactions even cheaper, reinforcing its suitability for microtransactions and tipping. The release also included performance optimizations and security patches ported from upstream Bitcoin Core.

The development team has discussed several forward-looking initiatives, including improvements to the network's scalability, the potential for layer-two solutions similar to Bitcoin's Lightning Network, and enhancements to the wallet software for improved user experience. The Dogecoin Foundation has published a development roadmap (the "Dogecoin Trailmap") outlining these goals, with an emphasis on making Dogecoin practical for everyday transactions at global scale.

Throughout its history, Dogecoin development has been characterized by a conservative approach to protocol changes. Major changes have been motivated by practical necessity rather than feature ambition, and the development team has prioritized network stability and backward compatibility. This conservative philosophy has contributed to Dogecoin's reliability and longevity, even as more technically ambitious projects have come and gone.

Conclusion

Dogecoin has proven that a cryptocurrency's value and longevity are determined not only by technical innovation but also by the strength and culture of its community. What began as a lighthearted parody of the cryptocurrency boom in late 2013 has endured for over a decade, maintaining continuous network operation, processing millions of transactions, and supporting one of the most engaged communities in the digital currency space.

The technical foundation inherited from Bitcoin and Litecoin has provided Dogecoin with robust security and proven reliability. The adoption of merge mining with Litecoin in 2014 was a pivotal decision that secured the network far beyond what its standalone economics could have supported, demonstrating pragmatic engineering in service of the project's survival. The Scrypt proof-of-work algorithm, one-minute block-time/" class="glossary-link" data-slug="block-time" title="block time">block time, and inflationary monetary policy combine to create a cryptocurrency that is well-suited for its intended use cases of tipping, microtransactions, and casual peer-to-peer payments.

Dogecoin's inflationary monetary policy, often criticized by proponents of hard-cap currencies, has proven to be a thoughtful design choice. The perpetual issuance ensures ongoing miner incentives, replaces lost coins, and encourages circulation rather than hoarding. The decreasing inflation rate over time means that Dogecoin's monetary policy will asymptotically approach — but never reach — a zero-inflation state, providing a balanced approach between the extremes of fixed supply and unconstrained issuance.

Perhaps most significantly, Dogecoin has demonstrated that accessibility and community engagement are powerful forces in the adoption of new financial technologies. By lowering the psychological and technical barriers to entry, Dogecoin has introduced millions of people to cryptocurrency and blockchain technology. Its culture of generosity and charitable giving has challenged the perception that cryptocurrency communities are primarily motivated by financial speculation.

As the cryptocurrency ecosystem continues to evolve, Dogecoin occupies a unique and valuable position. It is not attempting to be a platform for decentralized applications, a privacy-focused currency, or a solution to enterprise blockchain needs. Instead, it aims to be exactly what its community has always used it for: a fast, inexpensive, and accessible digital currency for everyday people. The simplicity of this mission, combined with the dedication of its community and developers, suggests that Dogecoin will continue to be a relevant and active cryptocurrency for years to come.