ReceiptsA receipt with a unique transaction identifier that proves that a sale occurred.
SignaturesSignatures on documents are a traditional form of non-repudiation.
Seals & StampsAnother traditional form of non-repudiation are seals and stamps such as Japanese hanko and inkan that are used to provide non-repudiation of documents, transactions and communications.
Notary ServicesIt is common for the signing of legal documents to be witnessed by a licensed notary. The notary ensures that the signature is authentic and not made under the undue influence of a third party.
Forensic ScienceA handwriting expert may be used by a legal service as a means of non-repudiation of signatures.
AuthenticationA user is authenticated according to multiple factors before performing a financial translation on a banking website. This makes it more difficult for the user to dispute a transaction such as a stock trade.
Audit TrailA financial website maintains a detailed record of each page visited including information such as IP addresses. This information can be used in digital forensics to prove the authenticity of a user action.
Digital SignaturesA ecommerce retailer accepts invoices from a supplier electronically using an integration interface. The interface authenticates the partner by confirming that they can decrypt a message that was encrypted using the public key found in the partner's digital certificate. This involves sending an encrypted hashcode and requiring the partner to decrypt it and send it back. An audit trail is created that includes the unique hashcode that was decrypted by the partner. The only way that the partner can realistically claim the transaction didn't happen to to claim their private key was compromised.
BlockchainBlockchain is a distributed ledger technology that provides non-repudiation with tamper-proof records of transactions.
Biometric AuthenticationBiometric authentication makes it difficult to claim that it wasn't you who used a device or accessed a location.
SurveillanceSurveillance cameras and other surveillance such as voice recordings can be used as a type of non-repudiation that can be used as proof that an individual took some action such as entering into a purchase agreement.
NotesNon-repudiation relies on the state of security surrounding authentication, authorization and transaction records. For example, if technologies existed that could easily simulate your biometric identity, this would no longer be a strong form of non-repudiation.
The ability to prove or disprove that something happened such as a financial transaction or legally binding signature.
A cornerstone of law, commerce and information security.