ISO 17090-4:2020 pdf download – Health informatics — Public key infrastructure — Part 4: Digital signatures for healthcare documents.
4 Target of application 4.1 Target system The target systems of this document are as follows: a) the digital signature library with the digital signature function and the digital signature verification function for the medical treatment application; b) the digital signature program and the digital signature verification program as the stand-alone software or with the medical treatment application; The following are out of the scope of application: a) the medical treatment application that does not process the digital signature data directly; b) the medical treatment application that processes the digital signature and the result of signature verification with the digital signature library, the specific digital signature program, or the specific digital signature verification program; c) the application interface and user interface; Figure 1 shows an example of the processing layer. The digital signature application layer (the digital signature library, the digital signature program, or the digital signature verification program) is the target scope of this example. Therefore, the following layer, CSP, and PKCS#11, is not within the targeted scope of this document. In HPKI, it is assumed that storage modules of the end entity subscriber private key conform to standards of levels equal to or higher than US FIPS 140-2 level 1. Also, in addition to the smart card, as illustrated in Figure 1, a system could use a USB token, software token, etc. as the medium that stores the private key.
4.2 Generation process The digital signature format is based on ETSI advanced digital signatures, where CAdES (CMS Advanced Digital Signature) [8] and XAdES (XML Advanced Digital Signature) [9] are described in this document. These specifications define the various formats according to purpose of operation. — ES: The format that has the digital signature value, data itself, and information about the signer. — ES-T: The format that has the signature timestamp in addition to the ES format. Signature timestamp is a trusted timestamp provided by a timestamp authority to prove the existence of the signature. — ES-C: The format that has validation data references in addition to the ES-T format. — ES-X: The format that has ES-C timestamp to protect validation data references. — ES-X Long: The format that has the ES-C format and revocation information for verification. — ES-A: The format that has an archive timestamp to protect the signature, the timestamps, and the validation data.