Blockchain fundamentals
Nodes, clients and RPC providers
An app can use a chain without independently verifying all the data it displays.
Research · History · Reference
All entries A–Z · 10 / 15
438 · Articles and references
Crypto history
Nomad trusted-root failure
A 2022 Nomad upgrade left a zero root trusted, allowing copied calls to process messages as valid.
Scam patterns
OAuth-consent phishing
A hostile application asks for access through a real identity-provider screen.
Crypto history
OneCoin without a public blockchain
OneCoin sold a cryptocurrency story while criminal cases established a global fraud.
Crypto history
OneCoin, 2026: asset recovery is not the same as repaying every victim
The compensation announcement describes recovered assets and a claims process, not a reversal of the original losses.
Crypto history
OneCoin: a cryptocurrency story without the promised system
Recruitment commissions, fabricated mining and an operator-controlled price: the evidence behind the OneCoin fraud and Greenwood’s conviction.
Market structure
Opaque insurance funds
A displayed fund balance hides ownership, withdrawals and cross-product liabilities.
Chains & networks
Optimism: fault proofs and withdrawal assumptions
A challenge mechanism is one part of a deployed rollup's security model.
Blockchain fundamentals
Optimistic rollups
Optimistic rollups publish state claims subject to challenges.
Blockchain fundamentals
Optimistic rollups: claims, challenges and the exit route
The security argument depends on what can be challenged and who can actually submit the challenge.
DeFi & governance
Oracle freshness: a valid number can still be unusable
Price source, update conditions and failure handling belong in the same review.
Market structure
Oracle override power
An administrator or small signer set can replace the price that drives credit and liquidation.
Market structure
Oracle staleness
A correctly signed price can be too old for the market being settled.
Markets & incentives · DeFi risk mechanics
Oracles and liquidation: when a price becomes an instruction
A number becomes dangerous when a contract uses it to decide borrowing capacity, settlement or liquidation.
DeFi & governance
Oracles: which price controls the contract?
A price feed has sources, update conditions and failure modes.
Scam patterns
OTC escrow impersonation
A supposed neutral escrow is controlled by a participant or accomplice.
DeFi & governance
Overcollateralised debt positions
A borrower locks assets worth more than debt under protocol valuations.
KOLs & promotion
Paid promotion: preserve the incentive trail
A public post and a private allocation can tell different parts of the story.
KOLs & promotion
Paid promotion: what the audience needs to know
Payment, token exposure and the presentation of the message all affect how an endorsement is understood.
Names, identity and web content
Passkeys and crypto wallets: easier login, a new recovery map
The origin-bound credential, the account’s authority and the backup system need separate inspection.
Web fundamentals
Password storage: why hashing and encryption serve different jobs
A login service usually needs to verify a password, not recover its original text.
Scam patterns
Peer-to-peer payment reversals
A counterparty buys irreversible crypto with reversible fiat.
Wallets & security
Permanent delegates: a control the holder cannot revoke
Mint-level authority changes what holding a token actually means.
Scam patterns
Permit phishing
An offchain signature authorises a token allowance without an immediate gas payment.
Wallets & security
Permit2: token approval and downstream signatures are separate permissions
Review the token's allowance to Permit2 and the spender authority granted through Permit2.
Market structure
Perpetual funding: a transfer between position holders
Funding helps align a perpetual contract with its reference market, but it also changes the cost of holding a trade.
Crypto history
PlusToken investment scheme
PlusToken marketed a wallet and investment return while authorities described a large pyramid scheme.
KOLs & promotion
PnL screenshots without cash reconciliation
A screenshot omits deposits, withdrawals, leverage, open losses and failed wallets.