Costo \ de \ minar \gg Costo \ de \ verificar
Costs for the attacker: * specialized hardware (ASICs) * electricity * infrastructure * lost economic opportunity * financial risk * social coordination Costs for the verifier: * a single hash per node * less than 1 ms per block ### 8.1. Accumulated security PoW creates a “cryptographic wall”:Seguridad \ de \ la \ cadena \propto PoW \ acumulado
No matter how many nodes exist: **security comes from the total work buried under each block**. ## 9. Economic incentives: game theory applied We could define mining as a strategic interaction between economic agents. ### 9.1. Block reward It is composed of:Recompensa = Subsidio + Fees
Subsidy:50 \times 2^{-n}
where $$n = número \ de \ halvings$$. ### 9.2. Aligned incentives * Miners → maximize profits * Nodes → verify rules * Users → want security * Developers → improve efficiency Incentives are set up to favor: * Honesty > Attack ### 9.3. Why attacking the network is irrational To rewrite old blocks you must redo all the accumulated PoW competing against all honest miners at a cost higher than the benefit. Even an attacker with 51%: * cannot steal funds * cannot modify rules * cannot create inflation * can only reverse their own payments And at a ruinous cost. ## 10. Global hashrate: security metricHashrate \ global \thickapprox TH/s
(terahashes/second)
The higher it is, the more expensive it is to attack the network. ### 10.1. Conceptual example If the network has:300 EH/s
(300 quintillion hashes/s)
An actor would have to match that power **just to compete**. ## 11. Mining pools Miners usually group into pools. Reasons: * reduce variance * stable income * share work The pool: Miners → send shares → Pool aggregates PoW → Pool produces block → Distributes reward ### 11.1. Does this increase centralization risk? Yes, but not as much as it seems: * changing pools is trivial * pools do not control private keys * they only coordinate work * if they abuse, miners migrate ## 12. Types of hardware in the history of mining | Era | Hardware | Efficiency | Duration | | ------------ | -------- | ---------- | -------- | | 2009 | CPU | Very low | Months | | 2010 | GPU | 50× CPU | \~1 year | | 2012 | FPGA | 10× GPU | Short | | 2013-present | ASIC | 1,000× GPU | Dominant | ASIC = `Application-Specific Integrated Circuit` ## 13. Mathematical models of block time Mining follows a **Poisson process**. Expected time per block:E[T]= \dfrac{1}{λ}
where:λ =\dfrac{dificultad}{hashrate}
Variability: some blocks take seconds, others hours. But the long-run mean converges to **\~10 minutes**. ## 14. Attacks on the PoW system ### 14.1. 51% attack Allows: * reversing own payments * censoring transactions (temporarily) Does not allow: * creating bitcoins * stealing funds * breaking signatures * changing consensus rules ### 14.2. Selfish mining Theory: miner withholds blocks to gain advantage. Reality: * requires threshold > 33% * not very profitable * easy to detect * partially solved with `BIP32`, P2P improvements and topologies ### 14.3. Timestamp attacks Manipulate time to adjust difficulty. Mitigation: * strict limits * allowed window ± 2h * nodes reject impossible timestamps ## 15. Why PoW is superior to PoS (according to original design) Cypherpunk / engineering perspective: * **Based on physics, not on wealth** * **Objective cost of attack** * **History protected with irreversible work** * **Australian Fairness → everyone can compete** * **Proven dynamics since 2009 without failures** PoW is a mechanism **neutral, resilient, verifiable and politically independent**. ## 16. Chapter conclusion Mining and Proof of Work are: * The physical security layer of Bitcoin * The source of its immutability * The engine of its issuance * The foundation of its consensus * The economic barrier against attackers PoW turns electricity into digital security. Difficulty adjustment turns fluctuations into stability. Incentives turn competition into collective protection. > Mining is not “wasting energy”.\ > It is **spending energy to prevent fraud**, a military function without violence. --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter: ``` GET https://www.notbank.com/learn/academy/en/bitcoin/mining.md?ask=