Method of generating a pseudonym associated with a communication device, a network node, computer program and computer program product

A method for providing privacy, the method being performed in a network node of a communications system and the method comprising:

• receiving a message comprising a first subscription identifier;
• using a sequence generator to generate a sequence of values;
• obtaining one or more values included in the sequence of values;
• obtaining a pseudonym embryo based on the obtained one or more values included in the generated sequence of values;
• applying a masking operation on the pseudonym embryo, wherein the masking operation comprises a one-to-one mapping;
• obtaining a pseudonym as an output of the masking operation applied to the pseudonym embryo;
• storing the pseudonym in a memory device such that the pseudonym is associated with the first subscription identifier;
• employing a transmitter to transmit the pseudonym to a communication device associated with the first subscription identifier, wherein
• the sequence generator comprises a feedback shift register (FSR) for producing the sequence of values, or
• the sequence generator implements a T-function for producing the sequence of values.

A computer program product comprising a non-transitory computer readable medium storing a computer program, the computer program comprising computer program code, which, when executed on at least one processor causes the at least one processor to perform a method comprising:

• receiving a message comprising a first subscription identifier;
• using a sequence generator to generate a sequence of values;
• obtaining one or more values included in the sequence of values;
• obtaining a pseudonym embryo based on the obtained one or more values included in the generated sequence of values;
• applying a masking operation on the pseudonym embryo, wherein the masking operation comprises a one-to-one mapping;
• obtaining a pseudonym as an output of the masking operation applied to the pseudonym embryo;
• storing the pseudonym in a memory device such that the pseudonym is associated with the first subscription identifier;
• employing a transmitter to transmit the pseudonym to a communication device associated with the first subscription identifier;
• reusing the one or more values included in the generated sequence of values to obtain a second pseudonym embryo based on the one or more values;
• obtaining a second pseudonym as output of a masking operation applied to the second pseudonym embryo;
• storing the second pseudonym in the memory device such that the second pseudonym is associated with a second subscription identifier that is different than the first subscription identifier;
• and
• employing the transmitter to transmit the second pseudonym to a second communication device associated with the second subscription identifier.

A network node for providing privacy, the network node comprising:

• memory;
• and
• processing circuitry connected to the memory, the processing circuitry comprising one or more processors, wherein the network node is configured to:
• obtain a first subscription identifier;
• use a sequence generator to generate a sequence of values;
• obtain one or more values included in the sequence of values;
• obtain a pseudonym embryo based on the obtained one or more values included in the generated sequence of values;
• apply a masking operation on the pseudonym embryo, wherein the masking operation comprises a one-to-one mapping;
• obtain a pseudonym as an output of the masking operation applied to the pseudonym embryo;
• store the pseudonym in a memory device such that the pseudonym is associated with the first subscription identifier;
• employ a transmitter to transmit the pseudonym to a communication device associated with the first subscription identifier;
• reuse the one or more values included in the generated sequence of values to obtain a second pseudonym embryo based on the one or more values;
• obtain a second pseudonym as output of a masking operation applied to the second pseudonym embryo;
• store the second pseudonym in the memory device such that the second pseudonym is associated with a second subscription identifier that is different than the first subscription identifier;
• and
• employ the transmitter to transmit the second pseudonym to a second communication device associated with the second subscription identifier.

A method for providing privacy, the method comprising:

• obtaining a first pseudonym;
• associating the first pseudonym with a first subscription identifier;
• transmitting the first pseudonym to a first communication device associated with the first subscription identifier;
• obtaining a second pseudonym;
• associating the second pseudonym with a second subscription identifier;
• transmitting the second pseudonym to a second communication device associated with the second subscription identifier, wherein
• obtaining the first pseudonym comprises:
• obtaining a first value included in a sequence of values and using the first value and a one-to-one mapping function to generate the first pseudonym,
• obtaining the second pseudonym comprises:
• obtaining a second value included in the sequence of values and using the second value and the one-to-one mapping function to generate the second pseudonym, and
• the second value follows the first value in the sequence of values.