hcrypto.analyzer
Class VigenereAnalyzer

java.lang.Object
  |
  +--java.awt.Component
        |
        +--java.awt.Container
              |
              +--java.awt.Window
                    |
                    +--java.awt.Frame
                          |
                          +--hcrypto.analyzer.AnalyzerFrame
                                |
                                +--hcrypto.analyzer.VigenereAnalyzer

All Implemented Interfaces:

javax.accessibility.Accessible, Analyzer, java.awt.image.ImageObserver, java.awt.MenuContainer, java.io.Serializable

public class VigenereAnalyzer

extends AnalyzerFrame

implements Analyzer

See Also:

Serialized Form

Inner classes inherited from class java.awt.Frame

java.awt.Frame.AccessibleAWTFrame

Inner classes inherited from class java.awt.Window

java.awt.Window.AccessibleAWTWindow

Inner classes inherited from class java.awt.Container

java.awt.Container.AccessibleAWTContainer

Inner classes inherited from class java.awt.Component

java.awt.Component.AccessibleAWTComponent

Field Summary

protected int[][]	contacts
protected int[]	kasiskiFactors
protected int	keywordLengthEstKasiski
protected int	keywordLengthEstStat
static int	MAX_BIGRAMS
static int	MAX_CONTACT
static int	MAX_FACTORS
static int	MAX_KEYWORD
protected int	nRepeatedBigrams
protected int	nSuperDisplacements
protected int[]	superDispl
protected int[]	superFactors
static double	SUPERPOSNUMBER

Fields inherited from class hcrypto.analyzer.AnalyzerFrame

display, HEIGHT, WIDTH

Fields inherited from class java.awt.Frame

CROSSHAIR_CURSOR, DEFAULT_CURSOR, E_RESIZE_CURSOR, HAND_CURSOR, ICONIFIED, MOVE_CURSOR, N_RESIZE_CURSOR, NE_RESIZE_CURSOR, NORMAL, NW_RESIZE_CURSOR, S_RESIZE_CURSOR, SE_RESIZE_CURSOR, SW_RESIZE_CURSOR, TEXT_CURSOR, W_RESIZE_CURSOR, WAIT_CURSOR

Fields inherited from class java.awt.Component

BOTTOM_ALIGNMENT, CENTER_ALIGNMENT, LEFT_ALIGNMENT, RIGHT_ALIGNMENT, TOP_ALIGNMENT

Fields inherited from interface hcrypto.analyzer.Analyzer

DECIPHER_LIMIT

Fields inherited from interface java.awt.image.ImageObserver

ABORT, ALLBITS, ERROR, FRAMEBITS, PROPERTIES, SOMEBITS

Constructor Summary

VigenereAnalyzer()

VigenereAnalyzer(TextStatistics ts)

Method Summary

void	computeBigramDistances(java.lang.String s)
protected java.lang.String	computeFactors(int[] factors, int displ)
void	computeSuperpositionAnalysis(java.lang.String s) This method performs a superposition test.
void	doAnalysis()
java.lang.String	estimateKeyword(int keyLen) To find the find the keyword we break the cryptogram into keyLen monoalphabetic cryptograms, each of which is obtained by a Caesar shift from the standard alphabet.
int	estimateKeywordLength(int[] factors)
int	getOptimalShift(int firstChar, int displ) This method performs a Chi-Square test to find the optimal Caesar shift on a polyalphabetic text.
java.lang.String	getReport()
protected void	insertBigram(char ch1, char ch2, int displ) This method inserts a bigram into a table of repeated bigrams where ch1 is the first character of the bigram, ch2 is the second character, and displ is the displacement from the previous occurrence of this bigram.
protected java.lang.String	retrieveBigram(int k) This method retieves the kth bigram from the table of repeated bigrams.
void	run()
void	setup(java.lang.String s)

Methods inherited from class hcrypto.analyzer.AnalyzerFrame

buildGUI, centerWindow

Methods inherited from class java.awt.Frame

addNotify, finalize, getAccessibleContext, getCursorType, getFrames, getIconImage, getMenuBar, getState, getTitle, isResizable, paramString, remove, removeNotify, setCursor, setIconImage, setMenuBar, setResizable, setState, setTitle

Methods inherited from class java.awt.Window

addWindowListener, applyResourceBundle, applyResourceBundle, dispose, getFocusOwner, getGraphicsConfiguration, getInputContext, getListeners, getLocale, getOwnedWindows, getOwner, getToolkit, getWarningString, hide, isShowing, pack, postEvent, processEvent, processWindowEvent, removeWindowListener, setCursor, show, toBack, toFront

Methods inherited from class java.awt.Container

add, add, add, add, add, addContainerListener, addImpl, countComponents, deliverEvent, doLayout, findComponentAt, findComponentAt, getAlignmentX, getAlignmentY, getComponent, getComponentAt, getComponentAt, getComponentCount, getComponents, getInsets, getLayout, getMaximumSize, getMinimumSize, getPreferredSize, insets, invalidate, isAncestorOf, layout, list, list, locate, minimumSize, paint, paintComponents, preferredSize, print, printComponents, processContainerEvent, remove, remove, removeAll, removeContainerListener, setFont, setLayout, update, validate, validateTree

Methods inherited from class java.awt.Component

action, add, addComponentListener, addFocusListener, addHierarchyBoundsListener, addHierarchyListener, addInputMethodListener, addKeyListener, addMouseListener, addMouseMotionListener, addPropertyChangeListener, addPropertyChangeListener, bounds, checkImage, checkImage, coalesceEvents, contains, contains, createImage, createImage, disable, disableEvents, dispatchEvent, enable, enable, enableEvents, enableInputMethods, firePropertyChange, getBackground, getBounds, getBounds, getColorModel, getComponentOrientation, getCursor, getDropTarget, getFont, getFontMetrics, getForeground, getGraphics, getHeight, getInputMethodRequests, getLocation, getLocation, getLocationOnScreen, getName, getParent, getPeer, getSize, getSize, getTreeLock, getWidth, getX, getY, gotFocus, handleEvent, hasFocus, imageUpdate, inside, isDisplayable, isDoubleBuffered, isEnabled, isFocusTraversable, isLightweight, isOpaque, isValid, isVisible, keyDown, keyUp, list, list, list, location, lostFocus, mouseDown, mouseDrag, mouseEnter, mouseExit, mouseMove, mouseUp, move, nextFocus, paintAll, prepareImage, prepareImage, printAll, processComponentEvent, processFocusEvent, processHierarchyBoundsEvent, processHierarchyEvent, processInputMethodEvent, processKeyEvent, processMouseEvent, processMouseMotionEvent, removeComponentListener, removeFocusListener, removeHierarchyBoundsListener, removeHierarchyListener, removeInputMethodListener, removeKeyListener, removeMouseListener, removeMouseMotionListener, removePropertyChangeListener, removePropertyChangeListener, repaint, repaint, repaint, repaint, requestFocus, reshape, resize, resize, setBackground, setBounds, setBounds, setComponentOrientation, setDropTarget, setEnabled, setForeground, setLocale, setLocation, setLocation, setName, setSize, setSize, setVisible, show, size, toString, transferFocus

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.awt.MenuContainer

getFont, postEvent

Field Detail

MAX_BIGRAMS

public static final int MAX_BIGRAMS

MAX_FACTORS

public static final int MAX_FACTORS

MAX_KEYWORD

public static final int MAX_KEYWORD

MAX_CONTACT

public static final int MAX_CONTACT

SUPERPOSNUMBER

public static final double SUPERPOSNUMBER

contacts

protected int[][] contacts

keywordLengthEstStat

protected int keywordLengthEstStat

keywordLengthEstKasiski

protected int keywordLengthEstKasiski

nRepeatedBigrams

protected int nRepeatedBigrams

nSuperDisplacements

protected int nSuperDisplacements

kasiskiFactors

protected int[] kasiskiFactors

superFactors

protected int[] superFactors

superDispl

protected int[] superDispl

Constructor Detail

VigenereAnalyzer

public VigenereAnalyzer()

VigenereAnalyzer

public VigenereAnalyzer(TextStatistics ts)
                 throws java.lang.NullPointerException

Method Detail

setup

public void setup(java.lang.String s)

Specified by:

setup in interface Analyzer

run

public void run()

Specified by:

run in interface Analyzer

getReport

public java.lang.String getReport()

Specified by:

getReport in interface Analyzer

insertBigram

protected void insertBigram(char ch1,
                            char ch2,
                            int displ)

This method inserts a bigram into a table of repeated bigrams where ch1 is the first character of the bigram, ch2 is the second character, and displ is the displacement from the previous occurrence of this bigram.

retrieveBigram

protected java.lang.String retrieveBigram(int k)

This method retieves the kth bigram from the table of repeated bigrams.

computeSuperpositionAnalysis

public void computeSuperpositionAnalysis(java.lang.String s)

This method performs a superposition test. It places the original text on one line and superposes a copy of the text, displaced by 1..MAX_KEYWORD positions, under the original text. Then it computes the number of coincidences that result between the two lines.

computeBigramDistances

public void computeBigramDistances(java.lang.String s)

doAnalysis

public void doAnalysis()

estimateKeywordLength

public int estimateKeywordLength(int[] factors)

estimateKeyword

public java.lang.String estimateKeyword(int keyLen)

To find the find the keyword we break the cryptogram into keyLen monoalphabetic cryptograms, each of which is obtained by a Caesar shift from the standard alphabet. So for each letter in the keyword, find its shift.

computeFactors

protected java.lang.String computeFactors(int[] factors,
                                          int displ)

getOptimalShift

public int getOptimalShift(int firstChar,
                           int displ)

This method performs a Chi-Square test to find the optimal Caesar shift on a polyalphabetic text. It assumes that every _displ_ character starting at _firstChar_ belongs to the same alphabet. It is used primarily for analyzing Vigenere-like and Caesar-shift cryptograms.

Parameters:

firstChar - - the location of the first character in the cryptotext

displ - - the displacement (keyword length) or cycle length