Base de conocimiento
Base de conocimiento: de la blockchain al código de un contrato inteligente
Los artículos siguen una ruta de aprendizaje. Empiece por lo básico, avance hasta cómo ejecuta el código la máquina virtual de Ethereum y lea un contrato de escrow real.
Ruta de aprendizaje
Nivel 1: Fundamentos
Palabras e ideas. No hace falta código. Para quien empieza a conocer las criptomonedas.
- 1EN
What is a blockchain, in plain words
How a blockchain works - a shared ledger nobody can rewrite alone. Blocks, hashes, consensus and why you can trust it.
3 min de lectura - 2EN
What is cryptocurrency and where do coins come from
How cryptocurrency works - how it resembles money and how it differs, where coins come from, what a coin and a token are, and why prices swing so much.
4 min de lectura - 3EN
Bitcoin vs Ethereum - the difference and why deals are built on Ethereum
Bitcoin and Ethereum compared - goals, accounting model, smart contracts, consensus and fees. Why guarantor deals run on Ethereum and its L2 networks.
3 min de lectura - 4EN
Hash functions in plain words - a data fingerprint that cannot be forged
What a hash function is, its properties, why a blockchain needs it, how keccak256 differs from SHA-256 and where you meet hashes every day.
3 min de lectura - 5EN
Public-key cryptography - how a signature proves it is you
How private and public keys work, where an address comes from, what an ECDSA digital signature is and why a wallet needs no password. With a clear example.
4 min de lectura - 6EN
Crypto wallet, address and seed phrase: how not to lose your money
How a crypto wallet works - private and public key, address, seed phrase, wallet types and the main security rules for a beginner.
4 min de lectura - 7EN
What is a smart contract and why you can trust it with money
A smart contract is a program on a blockchain that executes a deal's terms by itself. How it works, how it differs from an ordinary contract and what its risks are.
4 min de lectura - 8EN
Tokens and NFTs - what they are, how they differ and where they are used
An overview of tokens on Ethereum - fungible (ERC-20) and unique (NFTs, ERC-721 and ERC-1155), how they work, where they are used and what risks they carry.
3 min de lectura - 9EN
Stablecoins: USDT, USDC, DAI - how they differ and what the risks are
What a stablecoin is, how it holds a one-dollar price, how USDT, USDC and DAI differ, and which risks to consider when holding and accepting them in deals.
3 min de lectura - 10EN
dApps and DeFi - decentralised applications and finance without middlemen
What dApps and DeFi are, how decentralised exchanges (AMM) and lending work, what collateral and liquidation are, and the risks of decentralised finance.
3 min de lectura - 11EN
Escrow: how a deal with a guarantor works
What escrow is, how a classic guarantee differs from a smart contract, and how the roles of buyer, seller and guarantor protect both sides of a deal.
4 min de lectura - 12EN
Where escrow is used - 10 real-life scenarios with examples
Ten scenarios where a secure smart-contract deal is useful - freelance, goods, domains, rentals, B2B and more. What fits, what does not and what to look at.
3 min de lectura - 13EN
Scams in P2P deals: 10 red flags
How scammers cheat in deals between people - pressure, fake guarantors, phishing, swapped addresses. Ten warning signs and how escrow protects you.
4 min de lectura - 14EN
Glossary - blockchain, wallets, smart contracts and escrow from A to Z
A concise glossary of blockchain, wallets, transactions, tokens, security and Coin-Trust terms. Each term links to a detailed article.
5 min de lectura
Nivel 2: Práctica
Cómo funciona todo en la billetera y en las operaciones. Para quien ya usa una billetera.
- 15EN
The deal lifecycle - from offer to payout, step by step
A full walkthrough of a Coin-Trust deal: offer, acceptance, performance, completion, cancellation, expiry and dispute. Who can do what and how much they get.
5 min de lectura - 16EN
Network fees (gas), L1 and L2: which network to choose for a deal
What gas is and why fees differ on Ethereum, Base, Polygon and BNB Chain. How L1 and L2 work, what the fee consists of and how to pick a network.
4 min de lectura - 17EN
Layer 2 and rollups - how Ethereum became cheaper and faster
Why second-layer networks exist, how optimistic and ZK rollups work, what a sequencer and withdrawal are, and how an L2 like Base differs from the main network.
4 min de lectura - 18EN
How to choose a network for a deal - Ethereum, Base, Polygon or BNB Chain
A comparison of Coin-Trust networks by security, fees, tokens and speed. How to pick a network for the deal amount and the mistakes beginners make when choosing.
3 min de lectura - 19EN
Anatomy of a transaction: nonce, gas, mempool and confirmations
What happens from pressing "Sign" to confirmation in a block - transaction fields, nonce, mempool, inclusion in a block, finality and why transactions get stuck.
4 min de lectura - 20EN
ERC-20 and approve: why the “approval” and what unlimited means
How ERC-20 tokens (USDT, USDC, DAI) work, why a separate approve signature is needed before depositing and how to manage approvals safely.
4 min de lectura - 21EN
Wallet security checklist - 15 rules that protect your money
A practical checklist - how to store a seed phrase, separate wallets, check signatures and approvals, use a hardware wallet and what to do after a compromise.
4 min de lectura - 22EN
Phishing and address poisoning - how the attacks work and how to protect yourself
A breakdown of typical attacks on wallet users - fake sites, malicious signatures and approvals, fake support and address poisoning. With examples and defences.
4 min de lectura - 23EN
ENS - readable names instead of long Ethereum addresses
What ENS and .eth names are, how a name turns into an address, why it is convenient yet risky, how reverse resolution works and how to verify an address.
4 min de lectura - 24EN
Bridges between networks - how assets are moved and why it is the riskiest place
How blockchain bridges work (lock-and-mint, liquidity pools), how a native bridge differs from a third-party one, the known hacks and how to move money more safely.
3 min de lectura - 25EN
How to read Etherscan: checking a contract, a transaction and events
A practical guide to block explorers (Etherscan, Basescan, Polygonscan, BscScan) - how to check an address, a transaction, a contract, tokens and approvals.
4 min de lectura - 26EN
How to verify a smart contract before using it - a step-by-step guide
A step-by-step contract check through a block explorer - address, verified source code, owner and rights, proxies, events, and caution with tokens.
4 min de lectura - 27EN
Coin-Trust fees by example - how much you pay and to whom
A breakdown of the service fees: the 1% platform fee, the guarantor's rate (base and dispute) and gas. Tables for every deal outcome on a 1000 USDC example.
4 min de lectura - 28EN
How arbitration works in escrow: incentives, deadlocks and abuse protection
Dispute mechanics in the smart contract: the guarantor's two rates, the 30-day timeout with a 50/50 split, mutual cancellation and abuse protection.
5 min de lectura - 29EN
How to choose a guarantor - criteria, rates and red flags
Who can be a guarantor in Coin-Trust, by what criteria to choose one, how to agree on rates and what to watch for so that a dispute does not become a problem.
4 min de lectura - 30EN
Preparing for a dispute - what evidence to collect and how to present it
A practical guide for buyer and seller: what evidence a guarantor needs, how to preserve conversations, photos and video, and how to present your position.
4 min de lectura - 31EN
Hash commitment: fixing a deal's terms without revealing them
How a keccak256 hash records a contract's fingerprint on the blockchain without publishing the text, and why swapping the document becomes impossible.
5 min de lectura - 32EN
How to write deal terms that protect both sides
Drafting terms in practice: what to specify, how to describe results and deadlines, acceptance criteria, typical mistakes and templates for services and goods.
4 min de lectura - 33EN
Use case - a 1,500 USDC freelance project paid by stages
A step-by-step example of ordering development through escrow: splitting into stages, terms, client and contractor actions, fee calculation and a partial dispute.
4 min de lectura - 34EN
Use case - selling a physical item with delivery through escrow
A step-by-step example of selling a camera for 650 USDC to another country: the seller's offer, inspection terms, delivery, confirmation and a defect dispute.
4 min de lectura - 35EN
Use case - selling a domain and digital goods through escrow
How to safely sell a domain, account or licence for 2000 USDC: the risk of takeback, handover order, file verification by hash and the checking window.
5 min de lectura - 36EN
Multisig and timelock - managing a contract without a single point of failure
What a multisig (m of n) and a timelock are, how wallets like Safe work, which risks they close and which they do not, and how to use them for an owner or guarantor.
4 min de lectura
Nivel 3: Bajo el capó
Bytes, gas, Solidity y sutilezas de seguridad. Para desarrolladores y curiosos.
- 37EN
Ethereum accounts and state - EOAs, contracts and the world state
How Ethereum accounts work: EOA and contract, the four account fields, the world state, contract addresses and the units wei, gwei, ether.
4 min de lectura - 38EN
The EVM under the hood: stack, memory, storage, calldata and the cost of gas
How the Ethereum virtual machine executes a smart contract - the stack architecture, data areas, opcodes, operation prices and why storage packing saves money.
5 min de lectura - 39EN
A tour of the Solidity language - types, functions, errors and events by example
A short practical tour of Solidity for those who can read code: contract structure, types, visibility, modifiers, errors and events. Examples from the escrow.
4 min de lectura - 40EN
ABI: how a function call turns into bytes - selectors, calldata and events
How smart-contract calls are encoded - the function selector, argument alignment, dynamic types, custom errors and event topics, with real examples.
5 min de lectura - 41EN
Events and logs: eth_getLogs, bloom filters and public RPC limits
How smart-contract events work, how to read them via eth_getLogs, why public nodes cut the block range and how to build deal history without your own database.
5 min de lectura - 42EN
ERC-20 from scratch - writing a token in Solidity and analysing every line
A minimal ERC-20 implementation in Solidity: balances, transfers, allowances, events, common mistakes and why proven libraries are needed in production.
5 min de lectura - 43EN
Signatures in Ethereum - ECDSA, ecrecover, personal_sign and EIP-712
How a signature (r, s, v) is built, how a contract verifies it via ecrecover, how personal_sign and EIP-712 differ, and what permit and EIP-1271 are.
4 min de lectura - 44EN
Writing escrow in Solidity: the state machine and a real contract walkthrough
How an escrow contract is built in Solidity: statuses, transitions, access checks, events and payouts - a minimal version and the production contract.
8 min de lectura - 45EN
Integer math and rounding in smart contracts
Why Solidity has no fractions, how basis points work, the order of multiplication and division, overflow checks, mulDiv and calculating shares by subtraction.
5 min de lectura - 46EN
Storage layout and variable packing in Solidity
How a contract stores data in 32-byte slots, how variables are packed, where mappings and arrays live and how the Coin-Trust deal struct is laid out.
4 min de lectura - 47EN
Access-control patterns in smart contracts - owner, roles and deal parties
How contracts decide who may do what: Ownable and Ownable2Step, roles, checking deal parties, pauses and least privilege. A walkthrough using the escrow.
4 min de lectura - 48EN
Reentrancy, checks-effects-interactions and pull payments
How the reentrancy attack that hacked The DAO works and how to defend against it: operation order, ReentrancyGuard and deferred payments, using escrow.
6 min de lectura - 49EN
Non-standard tokens: USDT without a return value, fee-on-transfer and blacklists
What surprises ERC-20 tokens hide - USDT with no return value, transfer fees, address blocking, different decimals - and how an escrow contract defends itself.
5 min de lectura - 50EN
A catalogue of smart contract vulnerabilities: 12 classic mistakes and defences
An overview of frequent contract vulnerabilities: reentrancy, access control, overflow, oracles, signature replay, DoS. With examples and the escrow's defences.
5 min de lectura - 51EN
Proxies and upgradeable contracts - delegatecall, UUPS and the price of flexibility
How proxy contracts work, what delegatecall does, how Transparent and UUPS differ, why EIP-1967 slots are needed and why Coin-Trust chose an immutable contract.
5 min de lectura - 52EN
CREATE2: how the same contract address appears on four networks
How CREATE2 works: the address formula, salt and bytecode, and why the escrow contract has the same address on Ethereum, Base, Polygon and BNB Chain.
5 min de lectura - 53EN
Merkle trees and membership proofs - verifying millions of items with one hash
How a Merkle tree is built, what a root and a proof are, how a contract verifies an element's membership, where this is used and which attacks exist.
4 min de lectura - 54EN
Oracles and the oracle problem - how a blockchain learns about the outside world
Why a contract cannot learn a rate or an event result alone, how oracles work (Chainlink, TWAP), why price manipulation is dangerous and who the oracle is in escrow.
4 min de lectura - 55EN
Gas optimization in Solidity - 12 techniques and when they apply
Practical gas-saving techniques for smart contracts: storage packing, calldata, caching, immutable, unchecked and the main rule - never trade away security.
4 min de lectura - 56EN
EIP-1559 - how the Ethereum fee market works (base fee, tips and burning)
How fees work after the London upgrade - the base fee, the priority tip, maxFeePerGas, automatic 12.5% adjustment and ETH burning. With calculations and examples.
4 min de lectura - 57EN
Proof of Stake and finality - how Ethereum agrees on blocks
How Ethereum consensus works after The Merge: validators and stake, slots and epochs, finality in 13 minutes, slashing, reorgs and how many confirmations to wait.
4 min de lectura - 58EN
Rollups under the hood - batches, fraud proofs, ZK, blobs and withdrawals
The design of rollups: the sequencer and batches, publishing data (calldata and EIP-4844 blobs), fraud and validity proofs, forced inclusion and withdrawal to L1.
4 min de lectura - 59EN
MEV and front-running - who earns from transaction order and how
What MEV is, how sandwich attacks, arbitrage and liquidations work, how searchers, builders and MEV-Boost fit together and how to protect yourself.
4 min de lectura - 60EN
Account abstraction (ERC-4337) - smart wallets, gas sponsorship and access recovery
What account abstraction and ERC-4337 are: UserOperation, bundler, paymaster, smart-wallet advantages over an EOA, social recovery and the risks.
4 min de lectura - 61EN
HD wallets - how 12 words yield all your keys (BIP-39, BIP-32, BIP-44)
How a seed phrase turns into keys: BIP-39 entropy and wordlist, PBKDF2, the BIP-32 hierarchy, the BIP-44 path for Ethereum and the passphrase. With examples.
4 min de lectura - 62EN
Foundry for beginners - compiling, tests, fuzzing and a local network
A practical introduction to Foundry: installation, project structure, unit tests, vm cheatcodes, fuzzing and invariants, forge, cast and anvil, with an example.
6 min de lectura - 63EN
Testing smart contracts: unit, fuzz, invariants and static analysis
How contracts holding money are verified: unit tests, fuzzing, solvency invariants, evil token mocks, Slither and Mythril - with an escrow built in Foundry.
5 min de lectura - 64EN
Audits and bug bounties - how smart contracts are examined and how to read a report
How a smart contract audit proceeds, the severity levels, what an audit is not, how to read a report, and how bug bounties and auditing contests work.
4 min de lectura
Glosario
Definiciones breves de "blockchain" a "tarifa del garante", con enlaces a los artículos detallados.
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