6.DATA DOWNLOAD DIGITAL SIGNATURE MECHANISMSU.K.
CSM_032The Intelligent Dedicated Equipment (IDE) stores data received from an equipment (VU or card) during one download session within one physical data file. This file must contain the certificates MSi.C and EQT.C. The file contains digital signatures of data blocks as specified in Appendix 7 Data Downloading Protocols.U.K.
CSM_033Digital signatures of downloaded data shall use a digital signature scheme with appendix such, that downloaded data may be read without any decipherment if desired.U.K.
6.1. Signature generation U.K.
CSM_034Data signature generation by the equipment shall follow the signature scheme with appendix defined in reference [PKCS1] with the SHA-1 hash function:U.K.
Signature = EQT.SK[‘00’ || ‘01’ || PS || ‘00’ || DER(SHA-1(Data))]
PS = Padding string of octets with value ‘FF’ such that length is 128.
DER(SHA-1(M)) is the encoding of the algorithm ID for the hash function and the hash value into an ASN.1 value of type DigestInfo (distinguished encoding rules):
‘30’||‘21’||‘30’||‘09’||‘06’||‘05’||‘2B’||‘0E’||‘03’||‘02’||‘1A’||‘05’||‘00’||‘04’||‘14’||Hash Value.
6.2. Signature verification U.K.
CSM_035Data signature verification on downloaded data shall follow the signature scheme with appendix defined in reference [PKCS1] with the SHA-1 hash function.U.K.
The European public key EUR.PK needs to be known independently (and trusted) by the verifier.
The following table illustrates the protocol an IDE carrying a Control card can follow to verify the integrity of data downloaded and stored on the ESM (External Storage media). The control card is used to perform the decipherement of digital signatures. This function may in this case not be implemented in the IDE.
The equipment that has downloaded and signed the data to be analysed is denoted EQT.
