Commission Implementing Regulation (EU) 2016/799 of 18 March 2016 implementing Regulation (EU) No 165/2014 of the European Parliament and of the Council laying down the requirements for the construction, testing, installation, operation and repair of tachographs and their components (Text with EEA relevance) (c. 799)

ANNEX I C U.K. Requirements for construction, testing, installation, and inspection

Appendix 11

COMMON SECURITY MECHANISMS U.K.

PART B U.K. SECOND-GENERATION TACHOGRAPH SYSTEM

10. VU- CARD MUTUAL AUTHENTICATION AND SECURE MESSAGING U.K.

10.4. Chip Authentication and Session Key Agreement U.K.

CSM_179 In steps 5 and 8 above, the card and the vehicle unit shall use the key derivation function for AES session keys defined in [TR-03111], with the following precisions and changes: U.K.

• The value of the counter shall be ‘00 00 00 01’ for K_ENC and ‘00 00 00 02’ for K_MAC.

• The optional nonce r shall be used and shall be equal to N_PICC.

• For deriving 128-bits AES keys, the hashing algorithm to be used shall be SHA-256.

• For deriving 192-bits AES keys, the hashing algorithm to be used shall be SHA-384.

• For deriving 256-bits AES keys, the hashing algorithm to be used shall be SHA-512.

The length of the session keys (i.e. the length at which the hash is truncated) shall be linked to the size of the Card_MA key pair, as specified in CSM_50.