Making an attempt to know the blockchain higher. If personal keys are by no means revealed to the blockchain, what prevents me from falsely including a file to the blockchain with a transaction from particular person A, whose public key I do know, to my public key?
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A transaction is signed with your private key and so can be verified with your public key.
The signature is the part your missing here. You can not fake someone else’s signature without access to thier private key
All full nodes validate that the signature that only the correct private key can create is valid and enforce this on the blockchain. With cryptography you can make proofs easy to confirm and almost impossible to create without the correct key.
Thanks for the responses, they pointed me in the right direction. For posterity, this is the resource I found:
https://www.khanacademy.org/economics-finance-domain/core-finance/money-and-banking/bitcoin/v/bitcoin-digital-signatures
> what prevents me from falsely adding a record to the blockchain with a transaction from person A, whose public key I know, to my public key?
Bitcoin is not sent from person to person. A Bitcoin transaction has one or more inputs and one or more outputs. A transaction output is a coin. A transaction input spends exactly one coin from an older transaction. A coin can only be spent once
In your hypothetical example, your transaction is invalid because it is not spending an existing unspent coin
Learn about public key cryptography or asymmetrical cryptography.
RSA is one implementation of it, created in 1977 and still used today for creating asymmetrical keys.