org.spongycastle.pqc.crypto.gmss

Class GMSSRootCalc

java.lang.Object

org.spongycastle.pqc.crypto.gmss.GMSSRootCalc

public class GMSSRootCalc
extends java.lang.Object

This class computes a whole Merkle tree and saves the needed values for AuthPath computation. It is used for precomputation of the root of a following tree. After initialization, 2^H updates are required to complete the root. Every update requires one leaf value as parameter. While computing the root all initial values for the authentication path algorithm (treehash, auth, retain) are stored for later use.

Constructor Summary

Constructors

Constructor and Description
GMSSRootCalc(Digest digest, byte[][] statByte, int[] statInt, Treehash[] treeH, java.util.Vector[] ret) This constructor regenerates a prior treehash object
GMSSRootCalc(int heightOfTree, int K, GMSSDigestProvider digestProvider) Constructor

Method Summary

Modifier and Type	Method and Description
byte[][]	getAuthPath() returns the authentication path of the first leaf of the tree
java.util.Vector[]	getRetain() returns the retain stacks storing all right nodes near to the root
byte[]	getRoot() returns the finished root value
java.util.Vector	getStack() returns the shared stack
byte[][]	getStatByte() Returns the status byte array used by the GMSSPrivateKeyASN.1 class
int[]	getStatInt() Returns the status int array used by the GMSSPrivateKeyASN.1 class
Treehash[]	getTreehash() returns the initial treehash instances, storing value y_3(i)
void	initialize(java.util.Vector sharedStack) Initializes the calculation of a new root
void	initializeTreehashSeed(byte[] seed, int index) initializes the seeds for the treehashs of the tree precomputed by this class
java.lang.String	toString()
void	update(byte[] leaf) Updates the root with one leaf and stores the needed values in retain, treehash or authpath
void	update(byte[] seed, byte[] leaf) updates the root with one leaf and stores needed values in retain, treehash or authpath.
boolean	wasFinished() Method to check whether the instance has been finished or not
boolean	wasInitialized() Method to check whether the instance has been initialized or not

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

GMSSRootCalc

public GMSSRootCalc(Digest digest,
                    byte[][] statByte,
                    int[] statInt,
                    Treehash[] treeH,
                    java.util.Vector[] ret)

This constructor regenerates a prior treehash object

Parameters:

digest - an array of strings, containing the digest of the used hash function and PRNG and the digest of the corresponding provider

statByte - status bytes

statInt - status ints

GMSSRootCalc

public GMSSRootCalc(int heightOfTree,
                    int K,
                    GMSSDigestProvider digestProvider)

Constructor

Parameters:

heightOfTree - maximal height of the tree

digestProvider - an array of strings, containing the name of the used hash function and PRNG and the name of the corresponding provider

Method Detail

initialize

public void initialize(java.util.Vector sharedStack)

Initializes the calculation of a new root

Parameters:

sharedStack - the stack shared by all treehash instances of this tree

update

public void update(byte[] seed,
                   byte[] leaf)

updates the root with one leaf and stores needed values in retain, treehash or authpath. Additionally counts the seeds used. This method is used when performing the updates for TREE++.

Parameters:

seed - the initial seed for treehash: seedNext

leaf - the height of the treehash

update

public void update(byte[] leaf)

Updates the root with one leaf and stores the needed values in retain, treehash or authpath

initializeTreehashSeed

public void initializeTreehashSeed(byte[] seed,
                                   int index)

initializes the seeds for the treehashs of the tree precomputed by this class

Parameters:

seed - the initial seed for treehash: seedNext

index - the height of the treehash

wasInitialized

public boolean wasInitialized()

Method to check whether the instance has been initialized or not

Returns:

true if treehash was already initialized

wasFinished

public boolean wasFinished()

Method to check whether the instance has been finished or not

Returns:

true if tree has reached its maximum height

getAuthPath

public byte[][] getAuthPath()

returns the authentication path of the first leaf of the tree

Returns:

the authentication path of the first leaf of the tree

getTreehash

public Treehash[] getTreehash()

returns the initial treehash instances, storing value y_3(i)

Returns:

the initial treehash instances, storing value y_3(i)

getRetain

public java.util.Vector[] getRetain()

returns the retain stacks storing all right nodes near to the root

Returns:

the retain stacks storing all right nodes near to the root

getRoot

public byte[] getRoot()

returns the finished root value

Returns:

the finished root value

getStack

public java.util.Vector getStack()

returns the shared stack

Returns:

the shared stack

getStatByte

public byte[][] getStatByte()

Returns the status byte array used by the GMSSPrivateKeyASN.1 class

Returns:

The status bytes

getStatInt

public int[] getStatInt()

Returns the status int array used by the GMSSPrivateKeyASN.1 class

Returns:

The status ints

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

Returns:

a human readable version of the structure