METHOD FOR SECURELY TRANSMITTING A DIGITAL MESSAGE

摘要

A method is provided for securely transmitting a digital message that is transmitted by means of an electronic letter service. A user of the service has a computer with a functioning browser and an Internet connection, and the electronic letter service makes use of a TrustCenter. The user creates a password using his/her browser. A user password verifier is cryptographically derived from the password. The user password verifier is transmitted to the electronic letter service and stored on a storage medium. A user secret is generated from the password by means of a cryptographic derivation. The user secret constitutes the symmetrical key for the encryption of a user-specific user master secret. The user secret is encrypted using the public key of the TrustCenter and the encrypted user secret is transmitted to the electronic letter service, from where it is then forwarded to the TrustCenter.

主权项

1. A method for securely transmitting a digital message by means of an electronic letter service, whereby a user of the service has a system with a computer with a functioning browser running on it as well as an Internet connection, and the electronic letter service makes use of a TrustCenter, whereby an asymmetrical encryption method is installed on the TrustCenter,
characterized by the following steps
the user creates a password, making use of the system of the user;a user password verifier is cryptographically derived from the password;the user password verifier is transmitted to the electronic letter service and the user password verifier is stored on a storage medium of the electronic letter service;a user secret is cryptographically derived from the password;the user secret is encrypted using the public key of the TrustCenter;the encrypted user secret is transmitted to the electronic letter service;the encrypted user secret is transmitted from the electronic letter service to the TrustCenter, whereby the electronic letter service sends to the TrustCenter a function call for the generation of a user master secret;the user secret is decrypted in the TrustCenter;the user master secret is generated in the TrustCenter;a user ID is generated in the TrustCenter;the user master secret is encrypted with the user secret in the TrustCenter;the user ID as well as the user master secret encrypted with the user secret are transmitted from the TrustCenter to the electronic letter service;the user ID and the user master secret encrypted with the user secret are stored in the electronic letter service.