Digital Signature
A digital signature is cryptographic proof that a message or transaction was approved by the holder of a specific private key.
A digital signature is a piece of cryptographic data created with a private key to prove that a specific message, file, or blockchain transaction was authorized by that key’s holder. It does not reveal the private key itself. Anyone can use the matching public key to check that the signature is valid and that the signed data has not been changed since it was signed.
Digital signatures matter because they let blockchains verify ownership and authorization without relying on passwords, paper signatures, or a central gatekeeper. For example, when you send cryptocurrency from a wallet, your wallet signs the transaction with your private key. Network nodes then verify the signature using your public key before accepting it. A helpful comparison is a wax seal on a letter: it shows who approved the message and whether it was tampered with, but in digital signatures the check is mathematical rather than visual.
Other terms in Cryptography & Privacy
CoinJoin
A privacy technique that combines multiple users’ cryptocurrency payments into one transaction to make input-output links harder to trace.
Crypto Mixer
A service or protocol that blends cryptocurrency from many users to make transaction trails harder to trace on a public blockchain.
Fully Homomorphic Encryption
A cryptographic method that lets data be processed while still encrypted, so only the key holder can reveal the final result.
Hash Function
A hash function turns any input into a fixed-length string of data that is easy to verify but extremely hard to reverse or predict.