Distribution of Credentials

A method for distribution of a set of credentials from a credential issuer to a credential user, wherein the credential user is provided with a user device, wherein a first channel and a second channel are provided for communication between the user device and the credential issuer, wherein the method comprises, in a credential server, the steps of:

• generating a shared key and distributing the shared key to the user device or receiving a shared key from the user device via the second channel;
• generating a binary representation of the set of credentials with a predefined maximum level of deviation from a uniform distribution;
• encrypting the binary representation of the set of credentials by means of the shared key;
• and
• distributing the encrypted set of credentials via the first channel to the user device.

A computer program product for distribution of a set of credentials from a credential issuer to a credential user, wherein the credential user is provided with a user device, wherein a first channel and a second channel are provided for communication between the user device and the credential issuer, the computer program product comprising:

• a computer readable medium;
• first program instructions to distribute a shared key between the user device and the credential issuer by means of the second channel;
• second program instructions to generate a binary representation of the set of credentials with a predefined maximum level of deviation from a uniform distribution;
• third program instructions to encrypt the binary representation of the set of credentials by means of the shared key;
• fourth program instructions to distribute the encrypted set of credentials via the first channel from the credential issuer to the user device;
• fifth program instructions to decrypt the encrypted set of credentials by the user device by means of the shared key;
• and
• wherein the first, second, third, fourth and fifth program instructions are stored on the computer readable media.

A method for receiving a set of credentials from a credential server by a user device, wherein a first channel and a second channel are provided for communication between the user device and the credential server, wherein the method comprises, in the user device, the steps of:

• distributing a shared key between the user device and the credential issuer by means of the second channel;
• receiving a binary representation of the set of credentials with a predefined maximum level of deviation from a uniform distribution, wherein the binary representation of the set of credentials is encrypted by means of the shared key;
• decrypting the encrypted set of credentials by means of the shared key;
• and
• storing the decrypted set of credentials.

A system for distribution of a set of credentials from a credential issuer to a credential user, wherein the credential user is provided with a user device, wherein a first channel and a second channel are provided for communication between the user device and the credential issuer, the system comprising:

• a key shared between the user device and the credential issuer by means of the second channel;
• a binary representation of the set of credentials with a predefined maximum level of deviation from a uniform distribution;
• an encrypted set of credentials comprised of the binary representation of the set of credentials encrypted by means of the shared key, wherein the encrypted set of credentials is distributed via the first channel from the credential issuer to the user device;
• and
• a decrypted set of credentials comprised of the encrypted set of credentials decrypted by the user device by means of the shared key.