The confirmation of the confirmation procedure will not affect the reliability of the confirmation, because the confirmation of the confirmation procedure is based on the specific content of the confirmation, not a guess. Scientific and systematic methods are adopted in the identification of confirmation procedures to ensure the accuracy and reliability of confirmation. The identification of the confirmation procedure is mainly to prove the identity and qualification of the publisher according to the confirmed content, so as to ensure the reliability of the confirmation. Confirmation of the confirmation process can also ensure the integrity of the confirmation, for example, to prove that the publisher of the confirmation has completed all necessary steps in order to ensure the reliability of the confirmation. In addition, the confirmation of the confirmation procedure can also ensure the accuracy of the confirmation, such as proving that the certification materials used by the publisher of the confirmation are true and reliable. Moreover, the identification of the credit card program can also ensure the security of the credit card, for example, to prove that the publisher of the credit card did not use any untrustworthy information to publish the credit card. Therefore, it can be said with certainty that the identification of letter authentication program will not affect the reliability of letter authentication, but will help to ensure the reliability of letter authentication.