Encoding Method and Device for Securing a Counter Meter Reading Against Subsequential Manipulations, an Inspection Method and Device for Verifying the Authenticity a Counter Meter Reading

An encoding method for securing a counter reading of a counting unit against subsequent manipulation, comprising the steps of:

• when the counter reading is incremented or decremented by one count unit, activating the calculation of a new encoded counter reading,
• wherein the new encoded counter reading is calculated by applying a forward chained one-way function to an encoded counter reading, a range of the forward chained one-way function being contained in a domain of the forward chained one-way function.

An encoding device for executing an encoding method for securing a counter reading of a counting unit against any subsequent manipulation, comprising:

• a cryptographic counting unit storing an encoded counter reading and executing a process including the steps of calculating a new encoded counter reading when the counter reading of the counting unit is incremented or decremented by one count unit by applying a forward chained one-way function to the stored encoded counter reading, wherein a range of the forward chained one-way function is contained in the domain of the forward chained one-way function.

A verification device for executing a verification method for verifying the authenticity of a counter reading of a counting unit, comprising:

• a verification module executing a process including the steps of analyzing an encoded counter reading on the basis of a test counter reading, generating a positive status signal if the analysis yields that the encoded counter reading has been generated as a result of the counter reading, and generating a negative status signal if the analysis yields that the encoded counter reading has not been produced as a result of the counter reading, wherein the test counter reading indicates how often the counter reading of the counting unit has been incremented or decremented.