Struct atsamd_hal::aes::Ctype

pub struct Ctype(pub u8);

Hardware Countermeasures against Differential Power Analysis Attacks

The AES module features four types of hardware countermeasures that are useful for protecting data against differential power analysis attacks:

• Type 1: Randomly add one cycle to data processing
• Type 2: Randomly add one cycle to data processing (other version)
• Type 3: Add a random number of clock cycles to data processing, subject to a maximum of 11/13/15 clock cycles for key sizes of 128/192/256 bits
• Type 4: Add random spurious power consumption during data processing

By default, all countermeasures are enabled, but require a write in DRNGSEED register to be effective.

The countermeasures use random numbers generated by a deterministic random number generator embedded in AES module.

The seed for the random number generator is written to the RANDSEED register.

Note: also that a new seed must be written after a change in the keysize.

Note: that enabling countermeasures reduces AES module’s throughput. In short, the throughput is highest with all the countermeasures disabled.

Tuple Fields

0: u8

Trait Implementations

impl<T> BitRange<T> for Ctypewhere
    u8: BitRange<T>,

fn bit_range(&self, msb: usize, lsb: usize) -> T

Get a range of bits.

fn set_bit_range(&mut self, msb: usize, lsb: usize, value: T)

Set a range of bits.

impl Debug for Ctype

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.