Visual guide4 min
What problem does a blockchain solve?
A shared record is easy to copy. Agreeing which changes count is the harder part.
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Foundations
Start with what a shared record can establish, then meet the cryptographic tools that make independent checking possible. Hashes identify data, keys enable authorization, and nodes enforce rules. Understanding their separate roles makes the rest of the system easier to reason about.
What can a shared record establish?
What does a signature actually prove?
Who checks the rules?
In this collection
Interactive lesson3 min
Hashing explained: change one character and inspect the result
Turn a message into a fingerprint, then see how a tiny edit changes the result.
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Hashing versus encryption: why they solve different problems
One helps compare data. The other helps keep data confidential. Mixing them up breaks the design.
Read the guideVisual guide3 min
Private keys, public keys, and addresses
Three things often called “a wallet address” do very different jobs.
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What does a digital signature prove?
A valid signature connects a message to a key. It leaves several other questions unanswered.
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What nodes check, and why a blockchain needs consensus
Validity, willingness to relay, and choosing a history are three separate decisions.
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