A method for reloading first cryptographic program instructions in a security module currently in operation for protecting an electronic system by way of cryptography, which electronic system is associated with the security module, wherein the first cryptographic program instructions comprise a first cryptographic algorithm, wherein the security module comprises a preprogrammed non-volatile non-changeable read-only memory and a non-volatile changeable memory, wherein the security module also comprises initial cryptographic program instructions with an initial cryptographic algorithm for use of an initial cryptographic key associated with the initial cryptographic algorithm and having a first key length, wherein the initial cryptographic key is stored in a protected memory region of one of the two memories (102, 104), wherein the first cryptographic algorithm is configured for use of cryptographic keys which are associated with the first cryptographic algorithm and have a second key length, wherein the first key length is greater than the second key length, wherein the method comprises: • authenticating an external reload application, • following successful authentication, receiving the first cryptographic program instructions, • checking the validity of the first cryptographic program instructions by means of the initial cryptographic algorithm and the initial cryptographic key by executing the initial cryptographic program instructions, • on the condition that the check confirms the validity of the first cryptographic program instructions, installing the first cryptographic program instructions in the non-volatile changeable memory and using the first cryptographic program instructions to provide cryptographic data protection for the electronic system, wherein the first cryptographic program instructions at least partially replace second cryptographic program instructions stored in the non-volatile changeable memory, wherein the second cryptographic program instructions comprise a second cryptographic algorithm used for the cryptographic data protection for the electronic system, characterised in that the method also comprises: • deleting the parts of the second cryptographic program instructions that are to be replaced, wherein the replacement also comprises • placing a flag in the non-volatile changeable memory, which flag indicates that at least some of the second cryptographic program instructions should be replaced, • resetting the flag following completion of the installation of the first cryptographic program instructions, and wherein the replacement also comprises: • logging the individual steps of the replacement by way of log files, • revising the logged steps if the replacement is aborted without resetting of the flag. • authenticating an external reload application, • following successful authentication, receiving the first cryptographic program instructions, • checking the validity of the first cryptographic program instructions by means of the initial cryptographic algorithm and the initial cryptographic key by executing the initial cryptographic program instructions, • on the condition that the check confirms the validity of the first cryptographic program instructions, installing the first cryptographic program instructions in the non-volatile changeable memory and using the first cryptographic program instructions to provide cryptographic data protection for the electronic system, • deleting the parts of the second cryptographic program instructions that are to be replaced, wherein the replacement also comprises • placing a flag in the non-volatile changeable memory, which flag indicates that at least some of the second cryptographic program instructions should be replaced, • resetting the flag following completion of the installation of the first cryptographic program instructions, and • logging the individual steps of the replacement by way of log files, • revising the logged steps if the replacement is aborted without resetting of the flag.