Secure Hardware Extension, short form SHE: is a standard that specifies performing basic cryptography ciphers and managing cryptography keys via automotive Microcontrollers. SHE has been stated as standard in automotive microcontrollers to protect the cryptographic keys from software attacks by hardening them into the memory of the microcontroller and to perform basic symmetric cryptographic ciphers like AES & CMAC for encrypting and decrypting the data. SHE standard is implemented in microcontrollers by having an on-chip extension(peripheral) as a security subsystem which follows, the SHE standard.

SHE standard is stated by hersteller-initiative-software (HIS) consortium in April 2009. This consortium was founded in 2004 and consists of members from Audi, BMW, Daimler, Porsche, and Volkswagen to address activities and develop common automotive manufacturing standards.

SHE standard states that the peripheral in the Microcontroller should have the following 3 blocks, to implement SHE standard in MCU:

• Control Logic: Connecting the parts of the CPU to the microcontroller.
• Storage Area: To keep the cryptographic keys and additional corresponding information.
• Cryptographic cipher core: a hardware core or module to perform necessary calculations for performing cryptographic ciphers.