This Recommendation provides a non-repudiation framework based on one time password (OTP) to provide trust mechanisms between transaction entities. Also, this Recommendation describes the security requirements of OTP-based non-repudiation service as well as mechanisms for generating non-repudiation token. The sender may request a trusted third party (TTP) to generate the non-repudiation token of origin for the sender and also the recipient may request to verify the token of delivery for the recipient. Also, the TTP may generate the non-repudiation token of delivery for the recipient and verifies the token for the sender.