Cryptocurrency is a class of digital assets whose ownership and transfer are recorded on a cryptographically secured distributed ledger. A wallet or custodian uses private keys to authorise transactions, while network participants validate and order them under shared rules.
A blockchain is a distributed ledger that records ordered transactions or state changes in blocks. Each block normally references its predecessor and contains cryptographic commitments to its data. Nodes independently validate proposed blocks and use consensus and fork-choice rules to decide which history to accept.
Recognise how people actually get hit—account takeovers, scams, and malicious approvals—and the habits that keep you safe.
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Keys, signing, consensus, and the cryptography behind distributed key management.
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Learn who controls your assets, how keys fail, and how to make recovery possible.
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Cryptocurrency is a class of digital assets whose ownership and transfer are recorded on a cryptographically secured distributed ledger. A wallet or custodian uses private keys to authorise transactions, while network participants validate and order them under shared rules.
Bitcoin is a peer-to-peer electronic cash and settlement system launched in 2009. It records ownership on a public blockchain and uses proof of work plus independently validating nodes to prevent double-spending without a bank. Its native asset, bitcoin (BTC), is issued on a declining schedule that approaches 21 million units.
To buy cryptocurrency more safely, first set a strict loss limit, verify the exact legal entity in an official regulator register, secure both your exchange and email accounts with phishing-resistant authentication, compare the full cost before placing a small order, keep records, and withdraw only after checking the asset, network, destination and any required memo or tag.
A custody model is the arrangement that decides who controls the key able to move your crypto. Custodial services hold keys on your behalf, so you rely on the company. Single-key self-custody puts one key, and its seed phrase backup, entirely in your hands.
A key storage model is the arrangement that decides where a wallet's signing authority lives and what must be compromised, lost or coerced for assets to move. Software wallets hold keys on a connected device, trading safety for convenience. Hardware wallets isolate keys in a dedicated device designed to sign internally and keep key material inside.
A multisignature wallet is a custody arrangement that requires a threshold of independent keys, m of n, to authorise any transaction, enforced by the blockchain itself through a script or smart contract.
Two-factor authentication is an account security method that requires two independent proofs of identity before granting access: typically something you know, such as a password, plus something you have, such as a phone, an authenticator app or a hardware key. It protects an account even when the password leaks.
Crypto incident response is the sequence of actions that limits damage after assets or access are compromised: diagnose the type of breach, evacuate remaining funds from a clean device, revoke or freeze what the attacker can still use, secure surrounding accounts, report to platforms and law enforcement, and rebuild in a safer structure.
On-chain privacy is the degree to which blockchain activity can be linked to a real-world identity. Transparent blockchains publish every transaction, amount, address and timestamp forever, so privacy rests entirely on unlinkability: keeping addresses unconnected to each other and to a name.
Threshold cryptography distributes a cryptographic operation across several parties so no single party can act alone. In a t-of-n threshold signature, any authorised set of at least t participants can jointly produce one ordinary signature under one group public key, while fewer than t should not recover the signing key.
A crypto transaction is confirmed when it is included in a valid block on the chain a node currently considers canonical. One Bitcoin confirmation means inclusion in one block; further blocks add depth and reduce reorganisation risk. Ethereum also exposes explicit safe and finalised states.
Proof of work and proof of stake are mainly Sybil-resistance and block-proposer mechanisms inside larger consensus systems. Bitcoin links block production to computational work and selects the valid chain with the most accumulated work. Ethereum links proposal and voting weight to bonded ETH, uses LMD-GHOST fork choice and finalises checkpoints with Casper FFG.
A smart contract audit is a structured expert review of contract code that hunts for known vulnerability classes, deviations from specification and dangerous patterns before deployment. It is a point-in-time assessment of one code version under stated assumptions.
A cross-chain bridge is an interoperability system that moves value or messages between blockchains that cannot read each other. Typical designs lock assets in a contract on the source chain and mint a representation on the destination, with a verification layer, validators, a multisig, a light client or a proof system, attesting that the lock really happened.
Institutional crypto custody is a security and governance system that safeguards digital asset keys for organisations. It combines hardware isolation, distributed signing through MPC or multisignature, tiered storage, policy engines enforcing approvals and limits, independent audits and insurance, designed so that no single person, device or event should be able to lose or mov…
