pub struct Hc128Rng(/* private fields */);
Expand description
A cryptographically secure random number generator that uses the HC-128 algorithm.
HC-128 is a stream cipher designed by Hongjun Wu1, that we use as an RNG. It is selected as one of the “stream ciphers suitable for widespread adoption” by eSTREAM2.
HC-128 is an array based RNG. In this it is similar to RC-4 and ISAAC before it, but those have never been proven cryptographically secure (or have even been significantly compromised, as in the case of RC-43).
Because HC-128 works with simple indexing into a large array and with a few operations that parallelize well, it has very good performance. The size of the array it needs, 4kb, can however be a disadvantage.
This implementation is not based on the version of HC-128 submitted to the eSTREAM contest, but on a later version by the author with a few small improvements from December 15, 20094.
HC-128 has no known weaknesses that are easier to exploit than doing a brute-force search of 2128. A very comprehensive analysis of the current state of known attacks / weaknesses of HC-128 is given in Some Results On Analysis And Implementation Of HC-128 Stream Cipher5.
The average cycle length is expected to be 21024*32+10-1 = 232777. We support seeding with a 256-bit array, which matches the 128-bit key concatenated with a 128-bit IV from the stream cipher.
This implementation uses an output buffer of sixteen u32
words, and uses
BlockRng
to implement the RngCore
methods.
§References
Hongjun Wu (2008). “The Stream Cipher HC-128”. The eSTREAM Finalists, LNCS 4986, pp. 39–47, Springer-Verlag. ↩
Internet Engineering Task Force (February 2015), “Prohibiting RC4 Cipher Suites”. ↩
Hongjun Wu, Stream Ciphers HC-128 and HC-256 ↩
Shashwat Raizada (January 2015),“Some Results On Analysis And Implementation Of HC-128 Stream Cipher”. ↩
Trait Implementations§
source§impl RngCore for Hc128Rng
impl RngCore for Hc128Rng
source§fn fill_bytes(&mut self, dest: &mut [u8])
fn fill_bytes(&mut self, dest: &mut [u8])
dest
with random data. Read moresource§impl SeedableRng for Hc128Rng
impl SeedableRng for Hc128Rng
§type Seed = <Hc128Core as SeedableRng>::Seed
type Seed = <Hc128Core as SeedableRng>::Seed
u8
arrays (we recommend [u8; N]
for some N
). Read moresource§fn from_rng<R: RngCore>(rng: R) -> Result<Self, Error>
fn from_rng<R: RngCore>(rng: R) -> Result<Self, Error>
Rng
. Read moresource§fn seed_from_u64(state: u64) -> Self
fn seed_from_u64(state: u64) -> Self
u64
seed. Read moreimpl CryptoRng for Hc128Rng
Auto Trait Implementations§
impl Freeze for Hc128Rng
impl RefUnwindSafe for Hc128Rng
impl Send for Hc128Rng
impl Sync for Hc128Rng
impl Unpin for Hc128Rng
impl UnwindSafe for Hc128Rng
Blanket Implementations§
source§impl<T> BorrowMut<T> for Twhere
T: ?Sized,
impl<T> BorrowMut<T> for Twhere
T: ?Sized,
source§fn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
source§impl<T> CloneToUninit for Twhere
T: Clone,
impl<T> CloneToUninit for Twhere
T: Clone,
source§default unsafe fn clone_to_uninit(&self, dst: *mut T)
default unsafe fn clone_to_uninit(&self, dst: *mut T)
clone_to_uninit
)