diff --git a/src/main/java/com/mattrixwv/CipherStreamJava/monoSubstitution/Binary.java b/src/main/java/com/mattrixwv/CipherStreamJava/monoSubstitution/Binary.java
new file mode 100644
index 0000000..4877c56
--- /dev/null
+++ b/src/main/java/com/mattrixwv/CipherStreamJava/monoSubstitution/Binary.java
@@ -0,0 +1,96 @@
+//CipherStreamJava/src/main/java/com/mattrixwv/CipherStreamJava/monoSubstitution/Binary.java
+//Mattrixwv
+// Created: 01-08-22
+//Modified: 01-08-22
+package com.mattrixwv.CipherStreamJava.monoSubstitution;
+
+
+import java.util.StringJoiner;
+
+import com.mattrixwv.CipherStreamJava.exceptions.InvalidCharacterException;
+
+
+public class Binary{
+	private String inputString;		//The string that needs encoded/decoded
+	private String outputString;	//The encoded/decoded string
+
+	//Sets the input string
+	private void setInputStringEncode(String inputString){
+		this.inputString = inputString;
+	}
+	private void setInputStringDecode(String inputString) throws InvalidCharacterException{
+		this.inputString = inputString.replaceAll("[^01\\s]", "");
+		if(this.inputString != inputString){
+			throw new InvalidCharacterException("inputString cannot contain anything except 0's, 1's, and whitespace");
+		}
+	}
+	//Encode inputString, store it in outputString, and return it
+	private String encode(){
+		//Encode every character in inputString
+		StringJoiner output = new StringJoiner(" ");
+		for(int cnt = 0;cnt < inputString.length();++cnt){
+			//Get the next character
+			char ch = inputString.charAt(cnt);
+			//Encode the character to binary and add it to the output
+			output.add(Integer.toString(ch, 2));
+		}
+
+		//Save the output
+		outputString = output.toString();
+
+		//Return the output
+		return outputString;
+	}
+	//Decode inputString, store it in outputString, and return it
+	private String decode() throws InvalidCharacterException{
+		//Decode every binary number in the string
+		StringBuilder output = new StringBuilder();
+		for(String binary : inputString.split(" ")){
+			//Decode the current binary number
+			int num = Integer.valueOf(binary, 2);
+			//Make sure it is in a valid range
+			if((num < 0) && (num > 255)){
+				throw new InvalidCharacterException("The binary string '" + binary + "' is not a valid character");
+			}
+
+			//Convert the int to a char and save it
+			output.append((char)num);
+		}
+
+		//Save the output
+		outputString = output.toString();
+
+		//Return the output
+		return outputString;
+	}
+
+	//Constructor
+	public Binary(){
+		reset();
+	}
+	//Returns the inputString
+	public String getInputString(){
+		return inputString;
+	}
+	//Returns the outputString
+	public String getOutputString(){
+		return outputString;
+	}
+	//Sets the inputString and encodes the message
+	public String encode(String inputString){
+		reset();
+		setInputStringEncode(inputString);
+		return encode();
+	}
+	//Sets the inputString and decodes the message
+	public String decode(String inputString) throws InvalidCharacterException{
+		reset();
+		setInputStringDecode(inputString);
+		return decode();
+	}
+	//Makes sure all of the variables are empty
+	public void reset(){
+		inputString = "";
+		outputString = "";
+	}
+}
diff --git a/src/test/java/com/mattrixwv/CipherStreamJava/monoSubstitution/TestBinary.java b/src/test/java/com/mattrixwv/CipherStreamJava/monoSubstitution/TestBinary.java
new file mode 100644
index 0000000..b7c61f8
--- /dev/null
+++ b/src/test/java/com/mattrixwv/CipherStreamJava/monoSubstitution/TestBinary.java
@@ -0,0 +1,82 @@
+//CipherStreamJava/src/test/java/com/mattrixwv/CipherStreamJava/monoSubstitution/TestBinary.java
+//Mattrixwv
+// Created: 01-08-22
+//Modified: 01-08-22
+package com.mattrixwv.CipherStreamJava.monoSubstitution;
+
+
+import static org.junit.Assert.assertEquals;
+
+import com.mattrixwv.CipherStreamJava.exceptions.InvalidCharacterException;
+
+import org.junit.Test;
+
+
+public class TestBinary{
+	@Test
+	public void testDecode() throws InvalidCharacterException{
+		Binary cipher = new Binary();
+
+		//Test lowercase decoding
+		String inputString = "1100001";
+		String correctOutput = "a";
+		String output = cipher.decode(inputString);
+		assertEquals("Binary failed lowercase decoding.", correctOutput, output);
+		//Test uppercase decoding
+		inputString = "1000001";
+		correctOutput = "A";
+		output = cipher.decode(inputString);
+		assertEquals("Binary failed uppercase decoding.", correctOutput, output);
+
+		//Test whitespace decoding
+		inputString = "1000001 100000 1000010 1001 1000011 1010";
+		correctOutput = "A B\tC\n";
+		output = cipher.decode(inputString);
+		assertEquals("Binary failed whitespace decoding.", correctOutput, output);
+
+		//Test symbol decoding
+		inputString = "1000001 1000000 1000010 101101 1000011 101011";
+		correctOutput = "A@B-C+";
+		output = cipher.decode(inputString);
+		assertEquals("Binary failed symbol decoding.", correctOutput, output);
+
+		//Test mixed case, whitespace, and symbol decoding
+		inputString = "1000001 101011 1000010 1000000 1000011 100000 1100100 1001 1100101 1010 1100110";
+		correctOutput = "A+B@C d\te\nf";
+		output = cipher.decode(inputString);
+		assertEquals("Binary failed mixed case, whitespace, and symbol decoding.", correctOutput, output);
+	}
+	@Test
+	public void testEncode(){
+		Binary cipher = new Binary();
+
+		//Test lowercase encoding
+		String inputString = "a";
+		String correctOutput = "1100001";
+		String output = cipher.encode(inputString);
+		assertEquals("Binary failed lowercase encoding.", correctOutput, output);
+		//Test uppercase encoding
+		inputString = "A";
+		correctOutput = "1000001";
+		output = cipher.encode(inputString);
+		assertEquals("Binary failed uppercase encoding.", correctOutput, output);
+
+		//Test whitespace encoding
+		inputString = "A B\tC\n";
+		correctOutput = "1000001 100000 1000010 1001 1000011 1010";
+		output = cipher.encode(inputString);
+		assertEquals("Binary failed whitespace encoding.", correctOutput, output);
+
+		//Test symbol encoding
+		inputString = "A@B-C+";
+		correctOutput = "1000001 1000000 1000010 101101 1000011 101011";
+		output = cipher.encode(inputString);
+		assertEquals("Binary failed symbol encoding.", correctOutput, output);
+
+		//Test mixed case, whitespace, and symbol encoding
+		inputString = "A+B@C d\te\nf";
+		correctOutput = "1000001 101011 1000010 1000000 1000011 100000 1100100 1001 1100101 1010 1100110";
+		output = cipher.encode(inputString);
+		assertEquals("Binary failed mixed case, whitespace, and symbol encoding.", correctOutput, output);
+	}
+}