Struct SelfReferenceDecoy 

pub struct SelfReferenceDecoy;

Decoy strategy that draws bytes from the real key at random positions.

Threat profile. SelfReferenceDecoy is the strongest of the three built-in strategies and the recommended default. The decoy bytes are literally drawn from the key’s own byte distribution, so any statistical analysis of memory regions (byte-value histogram, entropy estimate, chi-squared distinguisher) will report identical profiles for real fragments and decoy fragments. An attacker has no statistical signal to separate them.

The only way for an attacker to recover the key, given this strategy, is to (a) obtain the position map (separately mlock’d) and (b) reverse the fragmentation. Statistical attacks alone do not work.

Why not just shuffle key bytes?

Sampling with replacement (which is what we do) is important: shuffling would still preserve the multiset of key bytes, and a long contiguous match would reveal a chunk boundary. With independent sampling, the decoy bytes match the key’s byte distribution without containing any contiguous run of key bytes long enough to be confirmed.

Examples

use key_vault::decoy::{DecoyStrategy, SelfReferenceDecoy};
use key_vault::RawKey;

let key = RawKey::new(vec![0xa1, 0xb2, 0xc3, 0xd4, 0xe5]);
let decoy = SelfReferenceDecoy.generate(&key, 32).unwrap();
assert_eq!(decoy.len(), 32);
// Every decoy byte is drawn from the key's byte set.
for b in &decoy {
    assert!([0xa1, 0xb2, 0xc3, 0xd4, 0xe5].contains(b));
}

Trait Implementations

impl Clone for SelfReferenceDecoy

fn clone(&self) -> SelfReferenceDecoy

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for SelfReferenceDecoy

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

Formats the value using the given formatter.

impl DecoyStrategy for SelfReferenceDecoy

fn generate(&self, key: &RawKey, output_len: usize) -> Result<Vec<u8>>

Generate output_len bytes of decoy material derived (or not) from key.

fn describe(&self) -> Cow<'_, str>

Short identifier for audit and error attribution.

impl Default for SelfReferenceDecoy

fn default() -> SelfReferenceDecoy

Returns the “default value” for a type.

impl Copy for SelfReferenceDecoy