diff --git a/src/main/java/mattrixwv/CipherStreamJava/Atbash.java b/src/main/java/mattrixwv/CipherStreamJava/Atbash.java
new file mode 100644
index 0000000..c6de8bf
--- /dev/null
+++ b/src/main/java/mattrixwv/CipherStreamJava/Atbash.java
@@ -0,0 +1,63 @@
+//CipherStreamJava/src/main/java/mattrixwv/CipherStreamJava/Atbash.java
+//Matthew Ellison
+// Created: 07-25-21
+//Modified: 07-25-21
+//This is the declaration of the Atbash class
+package mattrixwv.CipherStreamJava;
+
+
+public class Atbash{
+	public static final String version = "1.0";
+	private String inputString;		//Holds the string that needs encoded or decoded
+	private String outputString;	//Holds teh current version of the library
+	//Decodes inputString and stores in outputString
+	private String decode(){
+		//Stop through every element in the inputString and shift it the correct amount
+		for(int cnt = 0;cnt < inputString.length();++cnt){
+			outputString += (char)(inputString.charAt(cnt) + 25 - (2 * (inputString.charAt(cnt) - 'A')));
+		}
+
+		return outputString;
+	}
+	//Encodes inputString and stores in outputString
+	private String encode(){
+		//Step through every element in the inputString and shift it the correct amount
+		for(int cnt = 0;cnt < inputString.length();++cnt){
+			outputString += (char)(inputString.charAt(cnt) + 25 - (2 * (inputString.charAt(cnt) - 'A')));
+		}
+
+		return outputString;
+	}
+	//Removes all invalid characters and sets inputString
+	private void setInputString(String input){
+		//Convert all letters to uppercase
+		input = input.toUpperCase();
+		//Remove all characters except capital letters
+		input = input.replaceAll("[^A-Z]", "");
+		//Save the string
+		inputString = input;
+	}
+
+
+	public String getInputString(){
+		return inputString;
+	}
+	public String getOutputString(){
+		return outputString;
+	}
+	public String encode(String input){
+		//Make sure everything is empty before you begin
+		reset();
+		setInputString(input);
+		return encode();
+	}
+	public String decode(String input){
+		//Make sure everything is empty before you begin
+		reset();
+		setInputString(input);
+		return decode();
+	}
+	public void reset(){
+		inputString = outputString = "";
+	}
+}
diff --git a/src/test/java/mattrixwv/CipherStreamJava/TestAtbash.java b/src/test/java/mattrixwv/CipherStreamJava/TestAtbash.java
new file mode 100644
index 0000000..f7e48ee
--- /dev/null
+++ b/src/test/java/mattrixwv/CipherStreamJava/TestAtbash.java
@@ -0,0 +1,47 @@
+//CipherStreamJava/src/main/java/mattrixwv/CipherStreamJava/TestAtbash.java
+//Matthew Ellison
+// Created: 07-25-21
+//Modified: 07-25-21
+//These are the tests for the Atbash class
+package mattrixwv.CipherStreamJava;
+
+
+import static org.junit.Assert.assertEquals;
+
+import org.junit.Test;
+
+
+public class TestAtbash{
+	@Test
+	public void TestDecode(){
+		Atbash cipher = new Atbash();
+
+		//Test 1
+		String input = "zyx";
+		String correctOutput = "ABC";
+		String output = cipher.decode(input);
+		assertEquals("Atbash Decoding failed the first test", correctOutput, output);
+
+		//Test 2
+		input = "GSV JFRXP YILDM ULC QFNKH LEVI - GSV OZAB WLT";
+		correctOutput = "THEQUICKBROWNFOXJUMPSOVERTHELAZYDOG";
+		output = cipher.decode(input);
+		assertEquals("Atbash Decoding failed the second test", correctOutput, output);
+	}
+	@Test
+	public void TestEncode(){
+		Atbash cipher = new Atbash();
+
+		//Test 1
+		String input = "abc";
+		String correctOutput = "ZYX";
+		String output = cipher.encode(input);
+		assertEquals("Atbash Encoding failed the first test", correctOutput, output);
+
+		//Test 2
+		input = "The quick brown fox jumps over - the lazy dog";
+		correctOutput = "GSVJFRXPYILDMULCQFNKHLEVIGSVOZABWLT";
+		output = cipher.encode(input);
+		assertEquals("Atbash Encoding failed the second test", correctOutput, output);
+	}
+}