5. Distributed Blockchain

Now the same blockchain lives on three peers. Change block 4 on Peer B: only Peer B's copy breaks, and even if Peer B re-mines its blocks, its final hash won't match Peer A's and Peer C's. That's how a decentralized network spots a tampered copy without any central authority — just compare the latest hash.

Peer A

Block

Nonce Data Prev 0000000000000000000000000000000000000000000000000000000000000000 Hash 000015783b764259d382017d91a36d206d0600e2cbb3567748f46a33fe9297cf

Block

Nonce Data Prev 000015783b764259d382017d91a36d206d0600e2cbb3567748f46a33fe9297cf Hash 000012fa9b916eb9078f8d98a7864e697ae83ed54f5146bd84452cdafd043c19

Block

Nonce Data Prev 000012fa9b916eb9078f8d98a7864e697ae83ed54f5146bd84452cdafd043c19 Hash 0000b9015ce2a08b61216ba5a0778545bf4ddd7ceb7bbd85dd8062b29a9140bf

Block

Nonce Data Prev 0000b9015ce2a08b61216ba5a0778545bf4ddd7ceb7bbd85dd8062b29a9140bf Hash 0000ae8bbc96cf89c68be6e10a865cc47c6c48a9ebec3c6cad729646cefaef83

Block

Nonce Data Prev 0000ae8bbc96cf89c68be6e10a865cc47c6c48a9ebec3c6cad729646cefaef83 Hash 0000e4b9052fd8aae92a8afda42e2ea0f17972ea67cead67352e74dd6f7d217c

Peer B

Block

Nonce Data Prev 0000000000000000000000000000000000000000000000000000000000000000 Hash 000015783b764259d382017d91a36d206d0600e2cbb3567748f46a33fe9297cf

Block

Nonce Data Prev 000015783b764259d382017d91a36d206d0600e2cbb3567748f46a33fe9297cf Hash 000012fa9b916eb9078f8d98a7864e697ae83ed54f5146bd84452cdafd043c19

Block

Nonce Data Prev 000012fa9b916eb9078f8d98a7864e697ae83ed54f5146bd84452cdafd043c19 Hash 0000b9015ce2a08b61216ba5a0778545bf4ddd7ceb7bbd85dd8062b29a9140bf

Block

Nonce Data Prev 0000b9015ce2a08b61216ba5a0778545bf4ddd7ceb7bbd85dd8062b29a9140bf Hash 0000ae8bbc96cf89c68be6e10a865cc47c6c48a9ebec3c6cad729646cefaef83

Block

Nonce Data Prev 0000ae8bbc96cf89c68be6e10a865cc47c6c48a9ebec3c6cad729646cefaef83 Hash 0000e4b9052fd8aae92a8afda42e2ea0f17972ea67cead67352e74dd6f7d217c

Peer C

Block

Nonce Data Prev 0000000000000000000000000000000000000000000000000000000000000000 Hash 000015783b764259d382017d91a36d206d0600e2cbb3567748f46a33fe9297cf

Block

Nonce Data Prev 000015783b764259d382017d91a36d206d0600e2cbb3567748f46a33fe9297cf Hash 000012fa9b916eb9078f8d98a7864e697ae83ed54f5146bd84452cdafd043c19

Block

Nonce Data Prev 000012fa9b916eb9078f8d98a7864e697ae83ed54f5146bd84452cdafd043c19 Hash 0000b9015ce2a08b61216ba5a0778545bf4ddd7ceb7bbd85dd8062b29a9140bf

Block

Nonce Data Prev 0000b9015ce2a08b61216ba5a0778545bf4ddd7ceb7bbd85dd8062b29a9140bf Hash 0000ae8bbc96cf89c68be6e10a865cc47c6c48a9ebec3c6cad729646cefaef83

Block

Nonce Data Prev 0000ae8bbc96cf89c68be6e10a865cc47c6c48a9ebec3c6cad729646cefaef83 Hash 0000e4b9052fd8aae92a8afda42e2ea0f17972ea67cead67352e74dd6f7d217c

This interactive demo was created by Anders Brownworth and is rebuilt here as a self-hosted, dependency-free version. SHA-256 runs entirely in your browser; blocks turn red when their hash no longer starts with 0000 and green again once re-mined.