Patent ID: 8539610

Claim:
An apparatus comprising: at least one secure memory area comprising a plurality of pre-installed public keys for verifying software authenticity, wherein the plurality of pre-installed public keys have associated public key index numbers, and wherein the secure memory area comprises a current public key index number indicating currently used public key; at least one processor; and at least one memory including computer program code, the at least one memory and the computer program code being configured to, with the at least one processor, cause the apparatus at least to: receive an indication that a software package signed with a private key according to public key infrastructure has been received; receive a private key index number associated with the received software package; compare the received private key index number and the stored current public key index number; if the received private key index number is equal to the current public key index number, proceed to verify authenticity of the received software package using the public key associated with the private key; if the received private key index number is different from the current public key index number, to check, whether a public key associated with the received private key index number, is disabled; and if the public key associated with the received private key index number is disabled, prevent execution of the received software package, and otherwise, proceed to verify authenticity of the received software package using the public key associated with the private key.