Des (#4172)
* Update directory * Add DES Encryption algorithm * Update directory --------- Co-authored-by: github-actions <${GITHUB_ACTOR}@users.noreply.github.com>
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DIRECTORY.md
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DIRECTORY.md
@ -30,6 +30,7 @@
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* [Blowfish](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/ciphers/Blowfish.java)
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* [Blowfish](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/ciphers/Blowfish.java)
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* [Caesar](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/ciphers/Caesar.java)
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* [Caesar](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/ciphers/Caesar.java)
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* [ColumnarTranspositionCipher](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/ciphers/ColumnarTranspositionCipher.java)
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* [ColumnarTranspositionCipher](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/ciphers/ColumnarTranspositionCipher.java)
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* [DES](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/ciphers/DES.java)
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* [HillCipher](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/ciphers/HillCipher.java)
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* [HillCipher](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/ciphers/HillCipher.java)
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* [Polybius](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/ciphers/Polybius.java)
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* [Polybius](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/ciphers/Polybius.java)
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* [ProductCipher](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/ciphers/ProductCipher.java)
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* [ProductCipher](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/ciphers/ProductCipher.java)
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@ -151,14 +152,15 @@
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* [AVLSimple](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/trees/AVLSimple.java)
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* [AVLSimple](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/trees/AVLSimple.java)
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* [AVLTree](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/trees/AVLTree.java)
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* [AVLTree](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/trees/AVLTree.java)
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* [BinaryTree](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/trees/BinaryTree.java)
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* [BinaryTree](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/trees/BinaryTree.java)
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* [BSTFromSortedArray](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/trees/BSTFromSortedArray.java)
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* [BSTIterative](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/trees/BSTIterative.java)
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* [BSTIterative](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/trees/BSTIterative.java)
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* [BSTRecursive](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/trees/BSTRecursive.java)
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* [BSTRecursive](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/trees/BSTRecursive.java)
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* [BSTRecursiveGeneric](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/trees/BSTRecursiveGeneric.java)
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* [BSTRecursiveGeneric](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/trees/BSTRecursiveGeneric.java)
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* [CeilInBinarySearchTree](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/trees/CeilInBinarySearchTree.java)
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* [CeilInBinarySearchTree](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/trees/CeilInBinarySearchTree.java)
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* [CheckBinaryTreeIsValidBST](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/trees/CheckBinaryTreeIsValidBST.java)
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* [CheckIfBinaryTreeBalanced](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/trees/CheckIfBinaryTreeBalanced.java)
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* [CheckIfBinaryTreeBalanced](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/trees/CheckIfBinaryTreeBalanced.java)
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* [CheckTreeIsSymmetric](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/trees/CheckTreeIsSymmetric.java)
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* [CheckTreeIsSymmetric](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/trees/CheckTreeIsSymmetric.java)
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* [CreateBinaryTreeFromInorderPreorder](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/trees/CreateBinaryTreeFromInorderPreorder.java)
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* [CreateBinaryTreeFromInorderPreorder](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/trees/CreateBinaryTreeFromInorderPreorder.java)
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* [CreateBSTFromSortedArray](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/trees/CreateBSTFromSortedArray.java)
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* [FenwickTree](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/trees/FenwickTree.java)
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* [FenwickTree](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/trees/FenwickTree.java)
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* [GenericTree](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/trees/GenericTree.java)
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* [GenericTree](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/trees/GenericTree.java)
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* [InorderTraversal](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/trees/InorderTraversal.java)
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* [InorderTraversal](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/trees/InorderTraversal.java)
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@ -166,7 +168,6 @@
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* [LazySegmentTree](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/trees/LazySegmentTree.java)
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* [LazySegmentTree](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/trees/LazySegmentTree.java)
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* [LCA](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/trees/LCA.java)
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* [LCA](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/trees/LCA.java)
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* [LevelOrderTraversal](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/trees/LevelOrderTraversal.java)
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* [LevelOrderTraversal](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/trees/LevelOrderTraversal.java)
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* [LevelOrderTraversalHelper](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/trees/LevelOrderTraversalHelper.java)
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* [nearestRightKey](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/trees/nearestRightKey.java)
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* [nearestRightKey](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/trees/nearestRightKey.java)
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* [PostOrderTraversal](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/trees/PostOrderTraversal.java)
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* [PostOrderTraversal](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/trees/PostOrderTraversal.java)
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* [PreOrderTraversal](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/trees/PreOrderTraversal.java)
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* [PreOrderTraversal](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/trees/PreOrderTraversal.java)
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@ -175,9 +176,7 @@
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* [SameTreesCheck](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/trees/SameTreesCheck.java)
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* [SameTreesCheck](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/trees/SameTreesCheck.java)
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* [SegmentTree](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/trees/SegmentTree.java)
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* [SegmentTree](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/trees/SegmentTree.java)
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* [TreeRandomNode](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/trees/TreeRandomNode.java)
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* [TreeRandomNode](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/trees/TreeRandomNode.java)
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* [TreeTraversal](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/trees/TreeTraversal.java)
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* [TrieImp](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/trees/TrieImp.java)
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* [TrieImp](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/trees/TrieImp.java)
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* [ValidBSTOrNot](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/trees/ValidBSTOrNot.java)
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* [VerticalOrderTraversal](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/trees/VerticalOrderTraversal.java)
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* [VerticalOrderTraversal](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/trees/VerticalOrderTraversal.java)
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* [ZigzagTraversal](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/trees/ZigzagTraversal.java)
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* [ZigzagTraversal](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/trees/ZigzagTraversal.java)
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* devutils
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* devutils
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@ -202,6 +201,7 @@
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* [BoundaryFill](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/dynamicprogramming/BoundaryFill.java)
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* [BoundaryFill](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/dynamicprogramming/BoundaryFill.java)
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* [BruteForceKnapsack](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/dynamicprogramming/BruteForceKnapsack.java)
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* [BruteForceKnapsack](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/dynamicprogramming/BruteForceKnapsack.java)
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* [CatalanNumber](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/dynamicprogramming/CatalanNumber.java)
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* [CatalanNumber](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/dynamicprogramming/CatalanNumber.java)
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* [ClimbingStairs](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/dynamicprogramming/ClimbingStairs.java)
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* [CoinChange](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/dynamicprogramming/CoinChange.java)
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* [CoinChange](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/dynamicprogramming/CoinChange.java)
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* [CountFriendsPairing](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/dynamicprogramming/CountFriendsPairing.java)
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* [CountFriendsPairing](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/dynamicprogramming/CountFriendsPairing.java)
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* [DiceThrow](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/dynamicprogramming/DiceThrow.java)
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* [DiceThrow](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/dynamicprogramming/DiceThrow.java)
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@ -382,6 +382,7 @@
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* [KochSnowflake](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/others/KochSnowflake.java)
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* [KochSnowflake](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/others/KochSnowflake.java)
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* [Krishnamurthy](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/others/Krishnamurthy.java)
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* [Krishnamurthy](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/others/Krishnamurthy.java)
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* [LinearCongruentialGenerator](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/others/LinearCongruentialGenerator.java)
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* [LinearCongruentialGenerator](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/others/LinearCongruentialGenerator.java)
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* [LineSweep](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/others/LineSweep.java)
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* [LowestBasePalindrome](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/others/LowestBasePalindrome.java)
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* [LowestBasePalindrome](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/others/LowestBasePalindrome.java)
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* [Luhn](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/others/Luhn.java)
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* [Luhn](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/others/Luhn.java)
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* [Mandelbrot](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/others/Mandelbrot.java)
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* [Mandelbrot](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/others/Mandelbrot.java)
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* [StackPostfixNotation](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/others/StackPostfixNotation.java)
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* [StackPostfixNotation](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/others/StackPostfixNotation.java)
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* [StringMatchFiniteAutomata](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/others/StringMatchFiniteAutomata.java)
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* [StringMatchFiniteAutomata](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/others/StringMatchFiniteAutomata.java)
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* [Sudoku](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/others/Sudoku.java)
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* [Sudoku](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/others/Sudoku.java)
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* [ThreeSum](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/others/ThreeSum.java)
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* [TopKWords](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/others/TopKWords.java)
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* [TopKWords](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/others/TopKWords.java)
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* [TowerOfHanoi](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/others/TowerOfHanoi.java)
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* [TowerOfHanoi](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/others/TowerOfHanoi.java)
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* [TwoPointers](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/others/TwoPointers.java)
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* [TwoPointers](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/others/TwoPointers.java)
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* [LFSRTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/ciphers/a5/LFSRTest.java)
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* [LFSRTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/ciphers/a5/LFSRTest.java)
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* [BlowfishTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/ciphers/BlowfishTest.java)
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* [BlowfishTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/ciphers/BlowfishTest.java)
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* [CaesarTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/ciphers/CaesarTest.java)
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* [CaesarTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/ciphers/CaesarTest.java)
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* [DESTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/ciphers/DESTest.java)
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* [PolybiusTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/ciphers/PolybiusTest.java)
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* [PolybiusTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/ciphers/PolybiusTest.java)
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* [RSATest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/ciphers/RSATest.java)
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* [RSATest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/ciphers/RSATest.java)
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* [SimpleSubCipherTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/ciphers/SimpleSubCipherTest.java)
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* [SimpleSubCipherTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/ciphers/SimpleSubCipherTest.java)
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* [PriorityQueuesTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/datastructures/queues/PriorityQueuesTest.java)
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* [PriorityQueuesTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/datastructures/queues/PriorityQueuesTest.java)
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* trees
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* trees
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* [BinaryTreeTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/datastructures/trees/BinaryTreeTest.java)
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* [BinaryTreeTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/datastructures/trees/BinaryTreeTest.java)
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* [BSTFromSortedArrayTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/datastructures/trees/BSTFromSortedArrayTest.java)
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* [BSTIterativeTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/datastructures/trees/BSTIterativeTest.java)
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* [CeilInBinarySearchTreeTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/datastructures/trees/CeilInBinarySearchTreeTest.java)
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* [CeilInBinarySearchTreeTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/datastructures/trees/CeilInBinarySearchTreeTest.java)
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* [CheckBinaryTreeIsValidBSTTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/datastructures/trees/CheckBinaryTreeIsValidBSTTest.java)
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* [CheckTreeIsSymmetricTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/datastructures/trees/CheckTreeIsSymmetricTest.java)
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* [CheckTreeIsSymmetricTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/datastructures/trees/CheckTreeIsSymmetricTest.java)
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* [InorderTraversalTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/datastructures/trees/InorderTraversalTest.java)
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* [InorderTraversalTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/datastructures/trees/InorderTraversalTest.java)
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* [KDTreeTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/datastructures/trees/KDTreeTest.java)
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* [KDTreeTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/datastructures/trees/KDTreeTest.java)
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* [PreOrderTraversalTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/datastructures/trees/PreOrderTraversalTest.java)
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* [PreOrderTraversalTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/datastructures/trees/PreOrderTraversalTest.java)
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* [SameTreesCheckTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/datastructures/trees/SameTreesCheckTest.java)
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* [SameTreesCheckTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/datastructures/trees/SameTreesCheckTest.java)
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* [TreeTestUtils](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/datastructures/trees/TreeTestUtils.java)
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* [TreeTestUtils](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/datastructures/trees/TreeTestUtils.java)
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* [ValidBSTOrNotTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/datastructures/trees/ValidBSTOrNotTest.java)
|
|
||||||
* [VerticalOrderTraversalTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/datastructures/trees/VerticalOrderTraversalTest.java)
|
* [VerticalOrderTraversalTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/datastructures/trees/VerticalOrderTraversalTest.java)
|
||||||
* [ZigzagTraversalTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/datastructures/trees/ZigzagTraversalTest.java)
|
* [ZigzagTraversalTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/datastructures/trees/ZigzagTraversalTest.java)
|
||||||
* divideandconquer
|
* divideandconquer
|
||||||
@ -593,6 +596,7 @@
|
|||||||
* [StrassenMatrixMultiplicationTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/divideandconquer/StrassenMatrixMultiplicationTest.java)
|
* [StrassenMatrixMultiplicationTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/divideandconquer/StrassenMatrixMultiplicationTest.java)
|
||||||
* dynamicprogramming
|
* dynamicprogramming
|
||||||
* [CatalanNumberTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/dynamicprogramming/CatalanNumberTest.java)
|
* [CatalanNumberTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/dynamicprogramming/CatalanNumberTest.java)
|
||||||
|
* [climbStairsTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/dynamicprogramming/climbStairsTest.java)
|
||||||
* [EggDroppingTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/dynamicprogramming/EggDroppingTest.java)
|
* [EggDroppingTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/dynamicprogramming/EggDroppingTest.java)
|
||||||
* [KnapsackMemoizationTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/dynamicprogramming/KnapsackMemoizationTest.java)
|
* [KnapsackMemoizationTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/dynamicprogramming/KnapsackMemoizationTest.java)
|
||||||
* [LevenshteinDistanceTests](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/dynamicprogramming/LevenshteinDistanceTests.java)
|
* [LevenshteinDistanceTests](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/dynamicprogramming/LevenshteinDistanceTests.java)
|
||||||
@ -674,6 +678,7 @@
|
|||||||
* [CRCAlgorithmTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/others/CRCAlgorithmTest.java)
|
* [CRCAlgorithmTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/others/CRCAlgorithmTest.java)
|
||||||
* [FirstFitCPUTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/others/FirstFitCPUTest.java)
|
* [FirstFitCPUTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/others/FirstFitCPUTest.java)
|
||||||
* [KadaneAlogrithmTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/others/KadaneAlogrithmTest.java)
|
* [KadaneAlogrithmTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/others/KadaneAlogrithmTest.java)
|
||||||
|
* [LineSweepTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/others/LineSweepTest.java)
|
||||||
* [LinkListSortTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/others/LinkListSortTest.java)
|
* [LinkListSortTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/others/LinkListSortTest.java)
|
||||||
* [NewManShanksPrimeTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/others/NewManShanksPrimeTest.java)
|
* [NewManShanksPrimeTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/others/NewManShanksPrimeTest.java)
|
||||||
* [NextFitTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/others/NextFitTest.java)
|
* [NextFitTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/others/NextFitTest.java)
|
||||||
@ -731,6 +736,7 @@
|
|||||||
* [CheckAnagramsTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/strings/CheckAnagramsTest.java)
|
* [CheckAnagramsTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/strings/CheckAnagramsTest.java)
|
||||||
* [CheckVowelsTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/strings/CheckVowelsTest.java)
|
* [CheckVowelsTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/strings/CheckVowelsTest.java)
|
||||||
* [HammingDistanceTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/strings/HammingDistanceTest.java)
|
* [HammingDistanceTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/strings/HammingDistanceTest.java)
|
||||||
|
* [HorspoolSearchTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/strings/HorspoolSearchTest.java)
|
||||||
* [IsomorphicTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/strings/IsomorphicTest.java)
|
* [IsomorphicTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/strings/IsomorphicTest.java)
|
||||||
* [LetterCombinationsOfPhoneNumberTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/strings/LetterCombinationsOfPhoneNumberTest.java)
|
* [LetterCombinationsOfPhoneNumberTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/strings/LetterCombinationsOfPhoneNumberTest.java)
|
||||||
* [longestNonRepeativeSubstringTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/strings/longestNonRepeativeSubstringTest.java)
|
* [longestNonRepeativeSubstringTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/strings/longestNonRepeativeSubstringTest.java)
|
||||||
|
344
src/main/java/com/thealgorithms/ciphers/DES.java
Normal file
344
src/main/java/com/thealgorithms/ciphers/DES.java
Normal file
@ -0,0 +1,344 @@
|
|||||||
|
package com.thealgorithms.ciphers;
|
||||||
|
|
||||||
|
/**
|
||||||
|
* This class is build to demonstrate the application of the DES-algorithm on a
|
||||||
|
* plain English message. The supplied key must be in form of a 64 bit binary String.
|
||||||
|
*/
|
||||||
|
public class DES {
|
||||||
|
|
||||||
|
private String key;
|
||||||
|
private String subKeys[];
|
||||||
|
|
||||||
|
private void sanitize(String key) {
|
||||||
|
int length = key.length();
|
||||||
|
if (length != 64) {
|
||||||
|
throw new IllegalArgumentException("DES key must be supplied as a 64 character binary string");
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
DES(String key) {
|
||||||
|
sanitize(key);
|
||||||
|
this.key = key;
|
||||||
|
subKeys = getSubkeys(key);
|
||||||
|
}
|
||||||
|
|
||||||
|
public String getKey() {
|
||||||
|
return this.key;
|
||||||
|
}
|
||||||
|
|
||||||
|
public void setKey(String key) {
|
||||||
|
sanitize(key);
|
||||||
|
this.key = key;
|
||||||
|
}
|
||||||
|
|
||||||
|
//Permutation table to convert initial 64 bit key to 56 bit key
|
||||||
|
private static int[] PC1 =
|
||||||
|
{
|
||||||
|
57, 49, 41, 33, 25, 17, 9,
|
||||||
|
1, 58, 50, 42, 34, 26, 18,
|
||||||
|
10, 2, 59, 51, 43, 35, 27,
|
||||||
|
19, 11, 3, 60, 52, 44, 36,
|
||||||
|
63, 55, 47, 39, 31, 23, 15,
|
||||||
|
7, 62, 54, 46, 38, 30, 22,
|
||||||
|
14, 6, 61, 53, 45, 37, 29,
|
||||||
|
21, 13, 5, 28, 20, 12, 4
|
||||||
|
};
|
||||||
|
|
||||||
|
//Lookup table used to shift the initial key, in order to generate the subkeys
|
||||||
|
private static int[] KEY_SHIFTS =
|
||||||
|
{
|
||||||
|
1, 1, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 1
|
||||||
|
};
|
||||||
|
|
||||||
|
//Table to convert the 56 bit subkeys to 48 bit subkeys
|
||||||
|
private static int[] PC2 =
|
||||||
|
{
|
||||||
|
14, 17, 11, 24, 1, 5,
|
||||||
|
3, 28, 15, 6, 21, 10,
|
||||||
|
23, 19, 12, 4, 26, 8,
|
||||||
|
16, 7, 27, 20, 13, 2,
|
||||||
|
41, 52, 31, 37, 47, 55,
|
||||||
|
30, 40, 51, 45, 33, 48,
|
||||||
|
44, 49, 39, 56, 34, 53,
|
||||||
|
46, 42, 50, 36, 29, 32
|
||||||
|
};
|
||||||
|
|
||||||
|
//Initial permutatation of each 64 but message block
|
||||||
|
private static int[] IP =
|
||||||
|
{
|
||||||
|
58, 50, 42, 34, 26, 18, 10 , 2,
|
||||||
|
60, 52, 44, 36, 28, 20, 12, 4,
|
||||||
|
62, 54, 46, 38, 30, 22, 14, 6,
|
||||||
|
64, 56, 48, 40, 32, 24, 16, 8,
|
||||||
|
57, 49, 41, 33, 25, 17, 9, 1,
|
||||||
|
59, 51, 43, 35, 27, 19, 11, 3,
|
||||||
|
61, 53, 45, 37, 29, 21, 13, 5,
|
||||||
|
63, 55, 47, 39, 31, 23, 15, 7
|
||||||
|
};
|
||||||
|
|
||||||
|
//Expansion table to convert right half of message blocks from 32 bits to 48 bits
|
||||||
|
private static int[] expansion =
|
||||||
|
{
|
||||||
|
32, 1, 2, 3, 4, 5,
|
||||||
|
4, 5, 6, 7, 8, 9,
|
||||||
|
8, 9, 10, 11, 12, 13,
|
||||||
|
12, 13, 14, 15, 16, 17,
|
||||||
|
16, 17, 18, 19, 20, 21,
|
||||||
|
20, 21, 22, 23, 24, 25,
|
||||||
|
24, 25, 26, 27, 28, 29,
|
||||||
|
28, 29, 30, 31, 32, 1
|
||||||
|
};
|
||||||
|
|
||||||
|
//The eight substitution boxes are defined below
|
||||||
|
private static int[][] s1 = {
|
||||||
|
{14, 4, 13, 1, 2, 15, 11, 8, 3, 10, 6, 12, 5, 9, 0, 7},
|
||||||
|
{0, 15, 7, 4, 14, 2, 13, 1, 10, 6, 12, 11, 9, 5, 3, 8},
|
||||||
|
{4, 1, 14, 8, 13, 6, 2, 11, 15, 12, 9, 7, 3, 10, 5, 0},
|
||||||
|
{15, 12, 8, 2, 4, 9, 1, 7, 5, 11, 3, 14, 10, 0, 6, 13}
|
||||||
|
};
|
||||||
|
|
||||||
|
private static int[][] s2 = {
|
||||||
|
{15, 1, 8, 14, 6, 11, 3, 4, 9, 7, 2, 13, 12, 0, 5, 10},
|
||||||
|
{3, 13, 4, 7, 15, 2, 8, 14, 12, 0, 1, 10, 6, 9, 11, 5},
|
||||||
|
{0, 14, 7, 11, 10, 4, 13, 1, 5, 8, 12, 6, 9, 3, 2, 15},
|
||||||
|
{13, 8, 10, 1, 3, 15, 4, 2, 11, 6, 7, 12, 0, 5, 14, 9}
|
||||||
|
};
|
||||||
|
|
||||||
|
private static int[][] s3 = {
|
||||||
|
{10, 0, 9, 14, 6, 3, 15, 5, 1, 13, 12, 7, 11, 4, 2, 8},
|
||||||
|
{13, 7, 0, 9, 3, 4, 6, 10, 2, 8, 5, 14, 12, 11, 15, 1},
|
||||||
|
{13, 6, 4, 9, 8, 15, 3, 0, 11, 1, 2, 12, 5, 10, 14, 7},
|
||||||
|
{1, 10, 13, 0, 6, 9, 8, 7, 4, 15, 14, 3, 11, 5, 2, 12}
|
||||||
|
};
|
||||||
|
|
||||||
|
private static int[][] s4 = {
|
||||||
|
{7, 13, 14, 3, 0, 6, 9, 10, 1, 2, 8, 5, 11, 12, 4, 15},
|
||||||
|
{13, 8, 11, 5, 6, 15, 0, 3, 4, 7, 2, 12, 1, 10, 14, 9},
|
||||||
|
{10, 6, 9, 0, 12, 11, 7, 13, 15, 1, 3, 14, 5, 2, 8, 4},
|
||||||
|
{3, 15, 0, 6, 10, 1, 13, 8, 9, 4, 5, 11, 12, 7, 2, 14}
|
||||||
|
};
|
||||||
|
|
||||||
|
private static int[][] s5 = {
|
||||||
|
{2, 12, 4, 1, 7, 10, 11, 6, 8, 5, 3, 15, 13, 0, 14, 9},
|
||||||
|
{14, 11, 2, 12, 4, 7, 13, 1, 5, 0, 15, 10, 3, 9, 8, 6},
|
||||||
|
{4, 2, 1, 11, 10, 13, 7, 8, 15, 9, 12, 5, 6, 3, 0, 14},
|
||||||
|
{11, 8, 12, 7, 1, 14, 2, 13, 6, 15, 0, 9, 10, 4, 5, 3}
|
||||||
|
};
|
||||||
|
|
||||||
|
private static int[][] s6 = {
|
||||||
|
{12, 1, 10, 15, 9, 2, 6, 8, 0, 13, 3, 4, 14, 7, 5, 11},
|
||||||
|
{10, 15, 4, 2, 7, 12, 9, 5, 6, 1, 13, 14, 0, 11, 3, 8},
|
||||||
|
{9, 14, 15, 5, 2, 8, 12, 3, 7, 0, 4, 10, 1, 13, 11, 6},
|
||||||
|
{4, 3, 2, 12, 9, 5, 15, 10, 11, 14, 1, 7, 6, 0, 8, 13}
|
||||||
|
};
|
||||||
|
|
||||||
|
private static int[][] s7 = {
|
||||||
|
{4, 11, 2, 14, 15, 0, 8, 13 , 3, 12, 9 , 7, 5, 10, 6, 1},
|
||||||
|
{13 , 0, 11, 7, 4, 9, 1, 10, 14, 3, 5, 12, 2, 15, 8, 6},
|
||||||
|
{1, 4, 11, 13, 12, 3, 7, 14, 10, 15, 6, 8, 0, 5, 9, 2},
|
||||||
|
{6, 11, 13, 8, 1, 4, 10, 7, 9, 5, 0, 15, 14, 2, 3, 12}
|
||||||
|
};
|
||||||
|
|
||||||
|
private static int[][] s8 = {
|
||||||
|
{13, 2, 8, 4, 6, 15, 11, 1, 10, 9, 3, 14, 5, 0, 12, 7},
|
||||||
|
{1, 15, 13, 8, 10, 3, 7, 4, 12, 5, 6 ,11, 0, 14, 9, 2},
|
||||||
|
{7, 11, 4, 1, 9, 12, 14, 2, 0, 6, 10 ,13, 15, 3, 5, 8},
|
||||||
|
{2, 1, 14, 7, 4, 10, 8, 13, 15, 12, 9, 0, 3, 5, 6 ,11}
|
||||||
|
};
|
||||||
|
|
||||||
|
private static int[][][] s = {s1, s2, s3, s4, s5, s6, s7, s8};
|
||||||
|
|
||||||
|
//Permutation table, used in the feistel function post s-box usage
|
||||||
|
static int[] permutation =
|
||||||
|
{
|
||||||
|
16, 7, 20, 21,
|
||||||
|
29, 12, 28, 17,
|
||||||
|
1, 15, 23, 26,
|
||||||
|
5, 18, 31, 10,
|
||||||
|
2, 8, 24, 14,
|
||||||
|
32, 27, 3, 9,
|
||||||
|
19, 13, 30, 6,
|
||||||
|
22, 11, 4, 25
|
||||||
|
};
|
||||||
|
|
||||||
|
//Table used for final inversion of the message box after 16 rounds of Feistel Function
|
||||||
|
static int[] IPinverse =
|
||||||
|
{
|
||||||
|
40, 8, 48, 16, 56, 24, 64, 32,
|
||||||
|
39, 7, 47, 15, 55, 23, 63, 31,
|
||||||
|
38, 6, 46, 14, 54, 22, 62, 30,
|
||||||
|
37, 5, 45, 13, 53, 21, 61, 29,
|
||||||
|
36, 4, 44, 12, 52, 20, 60, 28,
|
||||||
|
35, 3, 43 ,11, 51, 19, 59, 27,
|
||||||
|
34, 2, 42, 10, 50, 18, 58, 26,
|
||||||
|
33, 1, 41, 9, 49, 17, 57, 25
|
||||||
|
};
|
||||||
|
|
||||||
|
private String[] getSubkeys(String originalKey) {
|
||||||
|
StringBuilder permutedKey = new StringBuilder(); //Initial permutation of keys via PC1
|
||||||
|
int i, j;
|
||||||
|
for (i = 0; i < 56; i++) {
|
||||||
|
permutedKey.append(originalKey.charAt(PC1[i] - 1));
|
||||||
|
}
|
||||||
|
String subKeys[] = new String[16];
|
||||||
|
String initialPermutedKey = permutedKey.toString();
|
||||||
|
String C0 = initialPermutedKey.substring(0, 28), D0 = initialPermutedKey.substring(28);
|
||||||
|
|
||||||
|
//We will now operate on the left and right halves of the permutedKey
|
||||||
|
for (i = 0; i < 16; i++) {
|
||||||
|
String Cn = C0.substring(KEY_SHIFTS[i]) + C0.substring(0, KEY_SHIFTS[i]);
|
||||||
|
String Dn = D0.substring(KEY_SHIFTS[i]) + D0.substring(0, KEY_SHIFTS[i]);
|
||||||
|
subKeys[i] = Cn + Dn;
|
||||||
|
C0 = Cn; //Re-assign the values to create running permutation
|
||||||
|
D0 = Dn;
|
||||||
|
}
|
||||||
|
|
||||||
|
//Let us shrink the keys to 48 bits (well, characters here) using PC2
|
||||||
|
for (i = 0; i < 16; i++) {
|
||||||
|
String key = subKeys[i];
|
||||||
|
permutedKey.setLength(0);
|
||||||
|
for (j = 0; j < 48; j++) {
|
||||||
|
permutedKey.append(key.charAt(PC2[j] - 1));
|
||||||
|
}
|
||||||
|
subKeys[i] = permutedKey.toString();
|
||||||
|
}
|
||||||
|
|
||||||
|
return subKeys;
|
||||||
|
}
|
||||||
|
|
||||||
|
private String XOR(String a, String b) {
|
||||||
|
int i, l = a.length();
|
||||||
|
StringBuilder xor = new StringBuilder();
|
||||||
|
for (i = 0; i < l; i++) {
|
||||||
|
int firstBit = a.charAt(i) - 48; // 48 is '0' in ascii
|
||||||
|
int secondBit = b.charAt(i) - 48;
|
||||||
|
xor.append((firstBit ^ secondBit));
|
||||||
|
}
|
||||||
|
return xor.toString();
|
||||||
|
}
|
||||||
|
|
||||||
|
private String createPaddedString(String s, int desiredLength, char pad) {
|
||||||
|
int i, l = s.length();
|
||||||
|
StringBuilder paddedString = new StringBuilder();
|
||||||
|
int diff = desiredLength - l;
|
||||||
|
for (i = 0; i < diff; i++) {
|
||||||
|
paddedString.append(pad);
|
||||||
|
}
|
||||||
|
return paddedString.toString();
|
||||||
|
}
|
||||||
|
|
||||||
|
private String pad(String s, int desiredLength) {
|
||||||
|
return createPaddedString(s, desiredLength, '0') + s;
|
||||||
|
}
|
||||||
|
|
||||||
|
private String padLast(String s, int desiredLength) {
|
||||||
|
return s + createPaddedString(s, desiredLength, '\u0000');
|
||||||
|
}
|
||||||
|
|
||||||
|
private String feistel(String messageBlock, String key) {
|
||||||
|
int i;
|
||||||
|
StringBuilder expandedKey = new StringBuilder();
|
||||||
|
for (i = 0; i < 48; i++) {
|
||||||
|
expandedKey.append(messageBlock.charAt(expansion[i] - 1));
|
||||||
|
}
|
||||||
|
String mixedKey = XOR(expandedKey.toString(), key);
|
||||||
|
StringBuilder substitutedString = new StringBuilder();
|
||||||
|
|
||||||
|
//Let us now use the s-boxes to transform each 6 bit (length here) block to 4 bits
|
||||||
|
for (i = 0; i < 48; i += 6) {
|
||||||
|
String block = mixedKey.substring(i, i + 6);
|
||||||
|
int row = (block.charAt(0) - 48) * 2 + (block.charAt(5) - 48);
|
||||||
|
int col = (block.charAt(1) - 48) * 8 + (block.charAt(2) - 48) * 4 + (block.charAt(3) - 48) * 2 + (block.charAt(4) - 48);
|
||||||
|
String substitutedBlock = pad(Integer.toBinaryString(s[i / 6][row][col]), 4);
|
||||||
|
substitutedString.append(substitutedBlock);
|
||||||
|
}
|
||||||
|
|
||||||
|
StringBuilder permutedString = new StringBuilder();
|
||||||
|
for (i = 0; i < 32; i++) {
|
||||||
|
permutedString.append(substitutedString.charAt(permutation[i] - 1));
|
||||||
|
}
|
||||||
|
|
||||||
|
return permutedString.toString();
|
||||||
|
}
|
||||||
|
|
||||||
|
private String encryptBlock(String message, String keys[]) {
|
||||||
|
StringBuilder permutedMessage = new StringBuilder();
|
||||||
|
int i;
|
||||||
|
for (i = 0; i < 64; i++) {
|
||||||
|
permutedMessage.append(message.charAt(IP[i] - 1));
|
||||||
|
}
|
||||||
|
String L0 = permutedMessage.substring(0, 32), R0 = permutedMessage.substring(32);
|
||||||
|
|
||||||
|
//Iterate 16 times
|
||||||
|
for (i = 0; i < 16; i++) {
|
||||||
|
String Ln = R0; // Previous Right block
|
||||||
|
String Rn = XOR(L0, feistel(R0, keys[i]));
|
||||||
|
L0 = Ln;
|
||||||
|
R0 = Rn;
|
||||||
|
}
|
||||||
|
|
||||||
|
String combinedBlock = R0 + L0; //Reverse the 16th block
|
||||||
|
permutedMessage.setLength(0);
|
||||||
|
for (i = 0; i < 64; i++) {
|
||||||
|
permutedMessage.append(combinedBlock.charAt(IPinverse[i] - 1));
|
||||||
|
}
|
||||||
|
return permutedMessage.toString();
|
||||||
|
}
|
||||||
|
|
||||||
|
//To decode, we follow the same process as encoding, but with reversed keys
|
||||||
|
private String decryptBlock(String message, String keys[]) {
|
||||||
|
String reversedKeys[] = new String[keys.length];
|
||||||
|
for (int i = 0; i < keys.length; i++) {
|
||||||
|
reversedKeys[i] = keys[keys.length - i - 1];
|
||||||
|
}
|
||||||
|
return encryptBlock(message, reversedKeys);
|
||||||
|
}
|
||||||
|
|
||||||
|
/**
|
||||||
|
* @param message Message to be encrypted
|
||||||
|
* @return The encrypted message, as a binary string
|
||||||
|
*/
|
||||||
|
public String encrypt(String message) {
|
||||||
|
StringBuilder encryptedMessage = new StringBuilder();
|
||||||
|
int l = message.length(), i, j;
|
||||||
|
if (l % 8 != 0) {
|
||||||
|
int desiredLength = (l / 8 + 1) * 8;
|
||||||
|
l = desiredLength;
|
||||||
|
message = padLast(message, desiredLength);
|
||||||
|
}
|
||||||
|
|
||||||
|
for (i = 0; i < l; i+= 8) {
|
||||||
|
String block = message.substring(i, i + 8);
|
||||||
|
StringBuilder bitBlock = new StringBuilder();
|
||||||
|
byte[] bytes = block.getBytes();
|
||||||
|
for (j = 0; j < 8; j++) {
|
||||||
|
bitBlock.append(pad(Integer.toBinaryString(bytes[j]), 8));
|
||||||
|
}
|
||||||
|
encryptedMessage.append(encryptBlock(bitBlock.toString(), subKeys));
|
||||||
|
}
|
||||||
|
return encryptedMessage.toString();
|
||||||
|
}
|
||||||
|
|
||||||
|
/**
|
||||||
|
* @param message The encrypted string. Expects it to be a multiple of 64 bits, in binary format
|
||||||
|
* @return The decrypted String, in plain English
|
||||||
|
*/
|
||||||
|
public String decrypt(String message) {
|
||||||
|
StringBuilder decryptedMessage = new StringBuilder();
|
||||||
|
int l = message.length(), i, j;
|
||||||
|
if (l % 64 != 0) {
|
||||||
|
throw new IllegalArgumentException("Encrypted message should be a multiple of 64 characters in length");
|
||||||
|
}
|
||||||
|
for (i = 0; i < l; i+= 64) {
|
||||||
|
String block = message.substring(i, i + 64);
|
||||||
|
String result = decryptBlock(block.toString(), subKeys);
|
||||||
|
byte res[] = new byte[8];
|
||||||
|
for (j = 0; j < 64; j+=8) {
|
||||||
|
res[j / 8] = (byte)Integer.parseInt(result.substring(j, j + 8), 2);
|
||||||
|
}
|
||||||
|
decryptedMessage.append(new String(res));
|
||||||
|
}
|
||||||
|
return decryptedMessage.toString().replace("\0", ""); // Get rid of the null bytes used for padding
|
||||||
|
}
|
||||||
|
|
||||||
|
}
|
51
src/test/java/com/thealgorithms/ciphers/DESTest.java
Normal file
51
src/test/java/com/thealgorithms/ciphers/DESTest.java
Normal file
@ -0,0 +1,51 @@
|
|||||||
|
package com.thealgorithms.ciphers;
|
||||||
|
|
||||||
|
import static org.junit.jupiter.api.Assertions.*;
|
||||||
|
|
||||||
|
import org.junit.jupiter.api.BeforeEach;
|
||||||
|
import org.junit.jupiter.api.Test;
|
||||||
|
|
||||||
|
//Test example taken from https://page.math.tu-berlin.de/~kant/teaching/hess/krypto-ws2006/des.htm
|
||||||
|
public class DESTest {
|
||||||
|
|
||||||
|
DES des;
|
||||||
|
|
||||||
|
@BeforeEach
|
||||||
|
public void setUp() {
|
||||||
|
des = new DES("0000111000110010100100100011001011101010011011010000110101110011");
|
||||||
|
}
|
||||||
|
|
||||||
|
@Test
|
||||||
|
void testEncrypt() {
|
||||||
|
//given
|
||||||
|
String plainText = "Your lips are smoother than vaseline\r\n";
|
||||||
|
//This is equal to c0999fdde378d7ed727da00bca5a84ee47f269a4d6438190d9d52f78f5358499828ac9b453e0e653 in hexadecimal
|
||||||
|
String expectedOutput = "11000000100110011001111111011101111000110111100011010111111" +
|
||||||
|
"011010111001001111101101000000000101111001010010110101000010011101110010001111111001" +
|
||||||
|
"001101001101001001101011001000011100000011001000011011001110101010010111101111000111" +
|
||||||
|
"101010011010110000100100110011000001010001010110010011011010001010011111000001110011001010011";
|
||||||
|
|
||||||
|
//when
|
||||||
|
String cipherText = des.encrypt(plainText);
|
||||||
|
|
||||||
|
//then
|
||||||
|
assertEquals(expectedOutput, cipherText);
|
||||||
|
}
|
||||||
|
|
||||||
|
@Test
|
||||||
|
void testDecrypt() {
|
||||||
|
//given
|
||||||
|
//This is equal to c0999fdde378d7ed727da00bca5a84ee47f269a4d6438190d9d52f78f5358499828ac9b453e0e653 in hexadecimal
|
||||||
|
String cipherText = "11000000100110011001111111011101111000110111100011010111111" +
|
||||||
|
"011010111001001111101101000000000101111001010010110101000010011101110010001111111001" +
|
||||||
|
"001101001101001001101011001000011100000011001000011011001110101010010111101111000111" +
|
||||||
|
"101010011010110000100100110011000001010001010110010011011010001010011111000001110011001010011";
|
||||||
|
String expectedOutput = "Your lips are smoother than vaseline\r\n";;
|
||||||
|
|
||||||
|
//when
|
||||||
|
String plainText = des.decrypt(cipherText);
|
||||||
|
|
||||||
|
//then
|
||||||
|
assertEquals(expectedOutput, plainText);
|
||||||
|
}
|
||||||
|
}
|
Loading…
Reference in New Issue
Block a user