What is a blockchain?¶

A blockchain is a shared transaction record maintained across a network according to agreed technical rules.

Avoid the dangerous assumption¶

The dangerous assumption is that every blockchain is identical, completely public, impossible to alter in any practical sense and automatically trustworthy.

A blockchain normally records transactions in groups or blocks that are linked to earlier records.

Network participants validate and add new transactions according to the rules of that system.

Public blockchains may allow anyone to inspect addresses, transaction hashes, amounts and transaction order.

Other systems may restrict access or expose less information.

A blockchain record can provide durable evidence that a transaction was accepted by the network and linked to particular addresses.

It does not identify the human beings behind those addresses.

It also does not explain why the transaction occurred, who controlled the keys or whether an exchange moved funds internally without recording every customer movement on-chain.

Different blockchains use different address formats, confirmation methods, fees, tokens and transaction structures.

Investigators should identify the correct network before tracing.

Preserve the transaction hash, wallet addresses, block number or height, amount, asset, timestamp and the source used to view the record.

Do not rely only on a screenshot from a blockchain explorer.

Record the underlying identifiers so the transaction can be checked again.

A displayed timestamp may reflect block inclusion rather than the exact moment the user initiated the transfer.

When reporting, distinguish the network record from provider-held account and user evidence.

Operational takeaway¶

Use the blockchain to establish recorded asset movement and transaction structure, while relying on provider, device and contextual evidence for personal attribution.