diff --git a/.github/workflows/gradle.yml b/.github/workflows/gradle.yml
index ac5db85..a6a3667 100644
--- a/.github/workflows/gradle.yml
+++ b/.github/workflows/gradle.yml
@@ -24,3 +24,19 @@ jobs:
     - name: Test with Gradle
       run: xvfb-run ./gradlew test --info
 
+  code_quality:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v2
+      - name: Set up JDK
+        uses: actions/setup-java@v1
+        with:
+          java-version: 11
+      - name: Grant execute permission for gradlew
+        run: chmod +x gradlew
+      - name: run style check on main source sets
+        run: ./gradlew checkstyleMain --info
+      - name: run style check on test source sets
+        run: ./gradlew checkstyleTest --info
+
diff --git a/build.gradle b/build.gradle
index d9bfad5..d324178 100755
--- a/build.gradle
+++ b/build.gradle
@@ -7,6 +7,13 @@ subprojects {
     apply plugin: 'java'
     apply plugin: 'org.javamodularity.moduleplugin'
 
+    apply plugin: 'checkstyle'
+
+    checkstyle {
+        toolVersion = '8.29'
+        configFile = rootProject.file('config/checkstyle/checkstyle.xml')
+    }
+
     repositories {
         jcenter()
         mavenCentral()
diff --git a/client/src/main/java/sigblockchain/projectred/client/AurumClient.java b/client/src/main/java/sigblockchain/projectred/client/AurumClient.java
index 88128c5..663e1c2 100644
--- a/client/src/main/java/sigblockchain/projectred/client/AurumClient.java
+++ b/client/src/main/java/sigblockchain/projectred/client/AurumClient.java
@@ -1,11 +1,11 @@
 package sigblockchain.projectred.client;
 
 
+import com.google.gson.Gson;
+import java.net.URI;
 import java.net.http.HttpClient;
 import java.net.http.HttpRequest;
 import java.net.http.HttpResponse;
-import java.net.URI;
-import com.google.gson.Gson;
 
 public class AurumClient {
 
diff --git a/client/src/main/java/sigblockchain/projectred/client/Block.java b/client/src/main/java/sigblockchain/projectred/client/Block.java
index 39bbd8f..9653f21 100644
--- a/client/src/main/java/sigblockchain/projectred/client/Block.java
+++ b/client/src/main/java/sigblockchain/projectred/client/Block.java
@@ -12,28 +12,34 @@ public class Block {
 	private final byte[][] data;            // [][]byte
 
 	/**
+	 * Stores data (typically contracts). The entire block is either added to the blockchain or the entirety
+	 * of it is rejected.
+	 *
 	 * @param version        Version of the blockChain the block was created on
-	 * @param height         A hex encoded 2's complement 64 bit integer string (without the prefix '0x'). Note, the height cannot be negative Represents the height of the block in the blockChain.
+	 * @param height         A hex encoded 2's complement 64 bit integer string (without the prefix '0x'). Note,
+	 *                       the height cannot be negative Represents the height of the block in the blockChain.
 	 * @param timestamp      Unix time, representing the number of nanoseconds elapsed since January 1, 1970 UTC
 	 * @param previousHash   Hash of the previous block
 	 * @param merkleRootHash Hash of the merkle-root of all inputs
 	 * @param dataLen        Number of objects in the Data section
 	 * @param data           Actual contents of block
 	 */
-	public Block(int version, String height, long timestamp, byte[] previousHash, byte[] merkleRootHash, int dataLen, byte[][] data) {
+  
+	public Block(int version, String height, long timestamp, byte[] previousHash,
+			byte[] merkleRootHash, int dataLen, byte[][] data) {
 		//Individual values Checking
-        if (checkUnsigned16(version)) {
-            throw new IllegalArgumentException("Invalid Input version");
-        }
-        if (!checkUnsigned64(new BigInteger(height, 16))) {
-            throw new IllegalArgumentException("Invalid Input height");
-        }
-        if (!checkSigned64(timestamp)) {
-            throw new IllegalArgumentException("Invalid Input timeStamp");
-        }
-        if (checkUnsigned16(dataLen)) {
-            throw new IllegalArgumentException("Invalid Input dataLen");
-        }
+		if (checkUnsigned16(version)) {
+			throw new IllegalArgumentException("Invalid Input version");
+		}
+		if (!checkUnsigned64(new BigInteger(height, 16))) {
+			throw new IllegalArgumentException("Invalid Input height");
+		}
+		if (!checkSigned64(timestamp)) {
+			throw new IllegalArgumentException("Invalid Input timeStamp");
+		}
+		if (checkUnsigned16(dataLen)) {
+			throw new IllegalArgumentException("Invalid Input dataLen");
+		}
 
 		this.height = new BigInteger(height, 16);
 		this.version = version;
@@ -49,7 +55,8 @@ private boolean checkUnsigned16(int value) {
 	}
 
 	private boolean checkUnsigned64(BigInteger value) {
-		return (value.compareTo(BigInteger.ZERO) >= 0) && (value.compareTo(new BigInteger("ffffffffffffffff", 16)) <= 0);
+		return (value.compareTo(BigInteger.ZERO) >= 0)
+				&& (value.compareTo(new BigInteger("ffffffffffffffff", 16)) <= 0);
 	}
 
 	private boolean checkSigned64(long value) {
@@ -57,49 +64,63 @@ private boolean checkSigned64(long value) {
 	}
 
 	/**
-	 * @return This function returns the value of version from the data
+	 * Returns the version of Aurum in which the block was added/created.
+	 *
+	 * @return int value of version. Will be guaranteed to be unsigned 16bit value
 	 */
 	public int getVersion() {
 		return this.version;
 	}
 
 	/**
-	 * @return This function returns the value of height from the data
+	 * Returns height of the block.
+	 *
+	 * @return int value of the height of the block. Will be positive value less than 2^64
 	 */
 	public BigInteger getHeight() {
 		return this.height;
 	}
 
 	/**
-	 * @return This function returns the value of timestamp from the data
+	 * Returns the unix timestamp of block.
+	 *
+	 * @return long timestamp.
 	 */
 	public long getTimestamp() {
 		return this.timestamp;
 	}
 
 	/**
-	 * @return This function returns the value of previousHash from the data
+	 * The hash of the previous block.
+	 *
+	 * @return byte array representing the hash
 	 */
 	public byte[] getPreviousHash() {
 		return this.previousHash;
 	}
 
 	/**
-	 * @return This function returns the value of merkleRootHash from the data
+	 * Returns the merkle root hash of the block.
+	 *
+	 * @return byte array representing the hash
 	 */
 	public byte[] getMerkleRootHash() {
 		return this.merkleRootHash;
 	}
 
 	/**
-	 * @return This function returns the value of dataLen from the data
+	 * Returns the length of data present in the block.
+	 *
+	 * @return int value, garuanteed to be unsigned 16 bit value
 	 */
 	public int getDataLen() {
 		return this.dataLen;
 	}
 
 	/**
-	 * @return This function returns the data from the data
+	 * Returns the data actually present in the block.
+	 *
+	 * @return An array of byte arrays.
 	 */
 	public byte[][] getData() {
 		return this.data;
diff --git a/client/src/test/java/sigblockchain/projectred/client/AccountTest.java b/client/src/test/java/sigblockchain/projectred/client/AccountTest.java
index 70b8f2a..416f0d3 100644
--- a/client/src/test/java/sigblockchain/projectred/client/AccountTest.java
+++ b/client/src/test/java/sigblockchain/projectred/client/AccountTest.java
@@ -3,7 +3,6 @@
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.fail;
 
-
 import java.math.BigInteger;
 import org.junit.jupiter.api.Test;
 
@@ -39,11 +38,14 @@ public void testAccountTest3() {
 		var addr = "81aaf16d7e4b626dc1c34c47bf9973496a3698a6e7ab0255af867169b43529fb";
 		var balance = new BigInteger("-2", 16);
 		var nonce = new BigInteger("-2", 16);
+
 		try {
 			Account account = new Account(addr, balance, nonce);
 			fail("Account object was allowed to be made with invalid arguments");
-		} catch (Exception ignored) {
+		} catch (Exception e) {
+			return;
 		}
+
 	}
 
 	@Test
diff --git a/client/src/test/java/sigblockchain/projectred/client/AurumClientTest.java b/client/src/test/java/sigblockchain/projectred/client/AurumClientTest.java
index a0c6ee2..86120c7 100644
--- a/client/src/test/java/sigblockchain/projectred/client/AurumClientTest.java
+++ b/client/src/test/java/sigblockchain/projectred/client/AurumClientTest.java
@@ -7,7 +7,6 @@
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertNotNull;
 
-
 import io.specto.hoverfly.junit.core.Hoverfly;
 import io.specto.hoverfly.junit.rule.HoverflyRule;
 import io.specto.hoverfly.junit5.HoverflyExtension;
@@ -30,6 +29,9 @@ public class AurumClientTest {
 
 	private static HoverflyRule hoverflyRule;
 
+	/**
+	 *  Gets a JSON resources from the resources directory.
+	 */
 	@BeforeAll
 	public static void setUpJsonResponse() {
 		var inputStream = ClassLoader.getSystemClassLoader().getResourceAsStream(jsonFile);
@@ -42,12 +44,11 @@ public static void setUpJsonResponse() {
 	}
 
 
-
 	@Test
 	public void testGetAccount(Hoverfly hoverfly) {
 		hoverfly.simulate(dsl(
-			service(host).
-				get(startsWith("/accountinfo"))
+			service(host)
+				.get(startsWith("/accountinfo"))
 				.queryParam("w", validAddress)
 				.willReturn(
 					success(validJson, "application/json"))
diff --git a/client/src/test/java/sigblockchain/projectred/client/BlockTest.java b/client/src/test/java/sigblockchain/projectred/client/BlockTest.java
index 20646cf..552534b 100644
--- a/client/src/test/java/sigblockchain/projectred/client/BlockTest.java
+++ b/client/src/test/java/sigblockchain/projectred/client/BlockTest.java
@@ -1,74 +1,70 @@
 package sigblockchain.projectred.client;
 
-import org.junit.jupiter.api.Test;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+
 import java.math.BigInteger;
-import static org.junit.jupiter.api.Assertions.*;
+import org.junit.jupiter.api.Test;
 
 class BlockTest {
 
-    private byte[] previousHash = "Previous Hash".getBytes();
-    private byte[] hash = "Block hash".getBytes();
-    private byte[][] data =
-            {
-                    {1, 2, 3, 4},
-                    {'H', 'E', 'L', 'L', 'O'},
-                    {5, 6, 7, 8},
-                    {'W', 'O', 'R', 'L', 'D'}
-            };
+	private byte[] previousHash = "Previous Hash".getBytes();
+	private byte[] hash = "Block hash".getBytes();
+	private byte[][] data = {{1, 2, 3, 4}, {'H', 'E', 'L', 'L', 'O'}, {5, 6, 7, 8}, {'W', 'O', 'R', 'L', 'D'}};
 
 
-    @Test
-    void testConstructor() {
-        Block block = new Block(10, "2B", -3556L, previousHash, hash, 10, data);
-        assertNotNull(block);
-    }
+	@Test
+	void testConstructor() {
+		Block block = new Block(10, "2B", -3556L, previousHash, hash, 10, data);
+		assertNotNull(block);
+	}
 
-    @Test
-    void testGetVersion() {
-        Block block = new Block(10, "2B", -3556L, previousHash, hash, 10, data);
-        int v = block.getVersion();
-        assertEquals(v, 10);
-    }
+	@Test
+	void testGetVersion() {
+		Block block = new Block(10, "2B", -3556L, previousHash, hash, 10, data);
+		int v = block.getVersion();
+		assertEquals(v, 10);
+	}
 
-    @Test
-    void testGetHeight() {
-        Block block = new Block(10, "2B", -3556L, previousHash, hash, 10, data);
-        var v = block.getHeight();
-        assertEquals(v, new BigInteger("2B", 16));
-    }
+	@Test
+	void testGetHeight() {
+		Block block = new Block(10, "2B", -3556L, previousHash, hash, 10, data);
+		var v = block.getHeight();
+		assertEquals(v, new BigInteger("2B", 16));
+	}
 
-    @Test
-    void testGetTimestamp() {
-        Block block = new Block(10, "2B", -3556L, previousHash, hash, 10, data);
-        long v = block.getTimestamp();
-        assertEquals(v, -3556L);
-    }
+	@Test
+	void testGetTimestamp() {
+		Block block = new Block(10, "2B", -3556L, previousHash, hash, 10, data);
+		long v = block.getTimestamp();
+		assertEquals(v, -3556L);
+	}
 
-    @Test
-    void testGetPreviousHash() {
-        Block block = new Block(10, "2B", -3556L, previousHash, hash, 10, data);
-        byte[] v = block.getPreviousHash();
-        assertEquals(v, previousHash);
-    }
+	@Test
+	void testGetPreviousHash() {
+		Block block = new Block(10, "2B", -3556L, previousHash, hash, 10, data);
+		byte[] v = block.getPreviousHash();
+		assertEquals(v, previousHash);
+	}
 
-    @Test
-    void testGetMerkleRootHash() {
-        Block block = new Block(10, "2B", -3556L, previousHash, hash, 10, data);
-        byte[] v = block.getMerkleRootHash();
-        assertEquals(v, hash);
-    }
+	@Test
+	void testGetMerkleRootHash() {
+		Block block = new Block(10, "2B", -3556L, previousHash, hash, 10, data);
+		byte[] v = block.getMerkleRootHash();
+		assertEquals(v, hash);
+	}
 
-    @Test
-    void testGetDataLen() {
-        Block block = new Block(10, "2B", -3556L, previousHash, hash, 10, data);
-        int v = block.getDataLen();
-        assertEquals(v, 10);
-    }
+	@Test
+	void testGetDataLen() {
+		Block block = new Block(10, "2B", -3556L, previousHash, hash, 10, data);
+		int v = block.getDataLen();
+		assertEquals(v, 10);
+	}
 
-    @Test
-    void testGetData() {
-        Block block = new Block(10, "2B", -3556L, previousHash, hash, 10, data);
-        byte[][] v = block.getData();
-        assertEquals(v, data);
-    }
+	@Test
+	void testGetData() {
+		Block block = new Block(10, "2B", -3556L, previousHash, hash, 10, data);
+		byte[][] v = block.getData();
+		assertEquals(v, data);
+	}
 }
diff --git a/config/checkstyle/checkstyle.xml b/config/checkstyle/checkstyle.xml
new file mode 100755
index 0000000..c42a183
--- /dev/null
+++ b/config/checkstyle/checkstyle.xml
@@ -0,0 +1,373 @@
+<?xml version="1.0"?>
+<!DOCTYPE module PUBLIC
+        "-//Checkstyle//DTD Checkstyle Configuration 1.3//EN"
+        "https://checkstyle.org/dtds/configuration_1_3.dtd">
+
+<!--
+    Checkstyle configuration that checks the Google coding conventions from Google Java Style
+    that can be found at https://google.github.io/styleguide/javaguide.html
+    Checkstyle is very configurable. Be sure to read the documentation at
+    http://checkstyle.org (or in your downloaded distribution).
+    To completely disable a check, just comment it out or delete it from the file.
+    To suppress certain violations please review suppression filters.
+    Authors: Max Vetrenko, Ruslan Diachenko, Roman Ivanov.
+ -->
+
+<module name = "Checker">
+    <property name="charset" value="UTF-8"/>
+    <property name="tabWidth" value="4"/>
+    <property name="severity" value="error"/>
+
+    <property name="fileExtensions" value="java, properties, xml"/>
+    <!-- Excludes all 'module-info.java' files              -->
+    <!-- See https://checkstyle.org/config_filefilters.html -->
+    <module name="BeforeExecutionExclusionFileFilter">
+        <property name="fileNamePattern" value="module\-info\.java$"/>
+    </module>
+
+    <!-- https://checkstyle.org/config_filters.html#SuppressionFilter -->
+    <module name="SuppressionFilter">
+        <property name="file" value="${org.checkstyle.google.suppressionfilter.config}"
+                  default="checkstyle-suppressions.xml" />
+        <property name="optional" value="true"/>
+    </module>
+
+
+    <module name="LineLength">
+        <property name="fileExtensions" value="java"/>
+        <property name="max" value="120"/>
+        <property name="ignorePattern" value="^package.*|^import.*|a href|href|http://|https://|ftp://"/>
+    </module>
+
+    <module name="TreeWalker">
+        <property name="tabWidth" value="4"/>
+        
+        <module name="RegexpSinglelineJava">
+            <property name="format" value="^\t* +\t*\S"/>
+            <property name="message" value="Line has leading space characters; indentation should be performed with tabs only."/>
+            <property name="ignoreComments" value="true"/>
+        </module>
+
+        <module name="OuterTypeFilename"/>
+        
+        <module name="IllegalTokenText">
+            <property name="tokens" value="STRING_LITERAL, CHAR_LITERAL"/>
+            <property name="format"
+                      value="\\u00(09|0(a|A)|0(c|C)|0(d|D)|22|27|5(C|c))|\\(0(10|11|12|14|15|42|47)|134)"/>
+            <property name="message"
+                      value="Consider using special escape sequence instead of octal value or Unicode escaped value."/>
+        </module>
+        
+        <module name="AvoidEscapedUnicodeCharacters">
+            <property name="allowEscapesForControlCharacters" value="true"/>
+            <property name="allowByTailComment" value="true"/>
+            <property name="allowNonPrintableEscapes" value="true"/>
+        </module>
+
+        <module name="AvoidStarImport"/>
+        
+        <module name="OneTopLevelClass"/>
+        
+        <module name="NoLineWrap">
+            <property name="tokens" value="PACKAGE_DEF, IMPORT, STATIC_IMPORT"/>
+        </module>
+
+        <module name="EmptyBlock">
+            <property name="option" value="TEXT"/>
+            <property name="tokens"
+                      value="LITERAL_TRY, LITERAL_FINALLY, LITERAL_IF, LITERAL_ELSE, LITERAL_SWITCH"/>
+        </module>
+
+        <module name="NeedBraces">
+            <property name="tokens"
+                      value="LITERAL_DO, LITERAL_ELSE, LITERAL_FOR, LITERAL_IF, LITERAL_WHILE"/>
+        </module>
+
+        <module name="LeftCurly">
+            <property name="tokens"
+                      value="ANNOTATION_DEF, CLASS_DEF, CTOR_DEF, ENUM_CONSTANT_DEF, ENUM_DEF,
+                    INTERFACE_DEF, LAMBDA, LITERAL_CASE, LITERAL_CATCH, LITERAL_DEFAULT,
+                    LITERAL_DO, LITERAL_ELSE, LITERAL_FINALLY, LITERAL_FOR, LITERAL_IF,
+                    LITERAL_SWITCH, LITERAL_SYNCHRONIZED, LITERAL_TRY, LITERAL_WHILE, METHOD_DEF,
+                    OBJBLOCK, STATIC_INIT"/>
+        </module>
+
+        <module name="RightCurly">
+            <property name="id" value="RightCurlySame"/>
+            <property name="tokens"
+                      value="LITERAL_TRY, LITERAL_CATCH, LITERAL_FINALLY, LITERAL_IF, LITERAL_ELSE,
+                    LITERAL_DO"/>
+        </module>
+
+        <module name="RightCurly">
+            <property name="id" value="RightCurlyAlone"/>
+            <property name="option" value="alone"/>
+            <property name="tokens"
+                      value="CLASS_DEF, METHOD_DEF, CTOR_DEF, LITERAL_FOR, LITERAL_WHILE, STATIC_INIT,
+                    INSTANCE_INIT, ANNOTATION_DEF, ENUM_DEF"/>
+        </module>
+
+        <module name="WhitespaceAround">
+            <property name="allowEmptyConstructors" value="true"/>
+            <property name="allowEmptyLambdas" value="true"/>
+            <property name="allowEmptyMethods" value="true"/>
+            <property name="allowEmptyTypes" value="true"/>
+            <property name="allowEmptyLoops" value="true"/>
+            <property name="tokens"
+                      value="ASSIGN, BAND, BAND_ASSIGN, BOR, BOR_ASSIGN, BSR, BSR_ASSIGN, BXOR,
+                    BXOR_ASSIGN, COLON, DIV, DIV_ASSIGN, DO_WHILE, EQUAL, GE, GT, LAMBDA, LAND,
+                    LCURLY, LE, LITERAL_CATCH, LITERAL_DO, LITERAL_ELSE, LITERAL_FINALLY,
+                    LITERAL_FOR, LITERAL_IF, LITERAL_RETURN, LITERAL_SWITCH, LITERAL_SYNCHRONIZED,
+                     LITERAL_TRY, LITERAL_WHILE, LOR, LT, MINUS, MINUS_ASSIGN, MOD, MOD_ASSIGN,
+                     NOT_EQUAL, PLUS, PLUS_ASSIGN, QUESTION, RCURLY, SL, SLIST, SL_ASSIGN, SR,
+                     SR_ASSIGN, STAR, STAR_ASSIGN, LITERAL_ASSERT, TYPE_EXTENSION_AND"/>
+            <message key="ws.notFollowed"
+                     value="WhitespaceAround: ''{0}'' is not followed by whitespace. Empty blocks may only be represented as '{}' when not part of a multi-block statement (4.1.3)"/>
+            <message key="ws.notPreceded"
+                     value="WhitespaceAround: ''{0}'' is not preceded with whitespace."/>
+        </module>
+
+        <module name="OneStatementPerLine"/>
+        
+        <module name="MultipleVariableDeclarations"/>
+        
+        <module name="ArrayTypeStyle"/>
+        <module name="MissingSwitchDefault"/>
+        <module name="FallThrough"/>
+        <module name="UpperEll"/>
+        <module name="ModifierOrder"/>
+        <module name="EmptyLineSeparator">
+            <property name="tokens"
+                      value="PACKAGE_DEF, IMPORT, STATIC_IMPORT, CLASS_DEF, INTERFACE_DEF, ENUM_DEF,
+                    STATIC_INIT, INSTANCE_INIT, METHOD_DEF, CTOR_DEF, VARIABLE_DEF"/>
+            <property name="allowNoEmptyLineBetweenFields" value="true"/>
+        </module>
+
+        <module name="SeparatorWrap">
+            <property name="id" value="SeparatorWrapDot"/>
+            <property name="tokens" value="DOT"/>
+            <property name="option" value="nl"/>
+        </module>
+
+        <module name="SeparatorWrap">
+            <property name="id" value="SeparatorWrapComma"/>
+            <property name="tokens" value="COMMA"/>
+            <property name="option" value="EOL"/>
+        </module>
+
+        <module name="SeparatorWrap">
+            <!-- ELLIPSIS is EOL until https://github.com/google/styleguide/issues/258 -->
+            <property name="id" value="SeparatorWrapEllipsis"/>
+            <property name="tokens" value="ELLIPSIS"/>
+            <property name="option" value="EOL"/>
+        </module>
+
+        <module name="SeparatorWrap">
+            <!-- ARRAY_DECLARATOR is EOL until https://github.com/google/styleguide/issues/259 -->
+            <property name="id" value="SeparatorWrapArrayDeclarator"/>
+            <property name="tokens" value="ARRAY_DECLARATOR"/>
+            <property name="option" value="EOL"/>
+        </module>
+
+        <module name="SeparatorWrap">
+            <property name="id" value="SeparatorWrapMethodRef"/>
+            <property name="tokens" value="METHOD_REF"/>
+            <property name="option" value="nl"/>
+        </module>
+
+        <module name="PackageName">
+            <property name="format" value="^[a-z]+(\.[a-z][a-z0-9]*)*$"/>
+            <message key="name.invalidPattern"
+                     value="Package name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+
+        <module name="TypeName">
+            <property name="tokens" value="CLASS_DEF, INTERFACE_DEF, ENUM_DEF, ANNOTATION_DEF"/>
+            <message key="name.invalidPattern"
+                     value="Type name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+
+        <module name="MemberName">
+            <property name="format" value="^[a-z][a-z0-9][a-zA-Z0-9]*$"/>
+            <message key="name.invalidPattern"
+                     value="Member name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+
+        <module name="ParameterName">
+            <property name="format" value="^[a-z]([a-z0-9][a-zA-Z0-9]*)?$"/>
+            <message key="name.invalidPattern"
+                     value="Parameter name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+
+        <module name="LambdaParameterName">
+            <property name="format" value="^[a-z]([a-z0-9][a-zA-Z0-9]*)?$"/>
+            <message key="name.invalidPattern"
+                     value="Lambda parameter name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+
+        <module name="CatchParameterName">
+            <property name="format" value="^[a-z]([a-z0-9][a-zA-Z0-9]*)?$"/>
+            <message key="name.invalidPattern"
+                     value="Catch parameter name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+
+        <module name="LocalVariableName">
+            <property name="format" value="^[a-z]([a-z0-9][a-zA-Z0-9]*)?$"/>
+            <message key="name.invalidPattern"
+                     value="Local variable name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+
+        <module name="ClassTypeParameterName">
+            <property name="format" value="(^[A-Z][0-9]?)$|([A-Z][a-zA-Z0-9]*[T]$)"/>
+            <message key="name.invalidPattern"
+                     value="Class type name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+
+        <module name="MethodTypeParameterName">
+            <property name="format" value="(^[A-Z][0-9]?)$|([A-Z][a-zA-Z0-9]*[T]$)"/>
+            <message key="name.invalidPattern"
+                     value="Method type name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+
+        <module name="InterfaceTypeParameterName">
+            <property name="format" value="(^[A-Z][0-9]?)$|([A-Z][a-zA-Z0-9]*[T]$)"/>
+            <message key="name.invalidPattern"
+                     value="Interface type name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+
+        <module name="NoFinalizer"/>
+        <module name="GenericWhitespace">
+            <message key="ws.followed"
+                     value="GenericWhitespace ''{0}'' is followed by whitespace."/>
+            <message key="ws.preceded"
+                     value="GenericWhitespace ''{0}'' is preceded with whitespace."/>
+            <message key="ws.illegalFollow"
+                     value="GenericWhitespace ''{0}'' should followed by whitespace."/>
+            <message key="ws.notPreceded"
+                     value="GenericWhitespace ''{0}'' is not preceded with whitespace."/>
+        </module>
+
+        <module name="Indentation">
+            <property name="basicOffset" value="4"/>
+            <property name="braceAdjustment" value="0"/>
+            <property name="caseIndent" value="4"/>
+            <property name="throwsIndent" value="4"/>
+            <property name="lineWrappingIndentation" value="4"/>
+            <property name="arrayInitIndent" value="4"/>
+        </module>
+
+        <module name="AbbreviationAsWordInName">
+            <property name="ignoreFinal" value="false"/>
+            <property name="allowedAbbreviationLength" value="1"/>
+            <property name="tokens"
+                      value="CLASS_DEF, INTERFACE_DEF, ENUM_DEF, ANNOTATION_DEF, ANNOTATION_FIELD_DEF,
+                    PARAMETER_DEF, VARIABLE_DEF, METHOD_DEF"/>
+        </module>
+
+        <module name="OverloadMethodsDeclarationOrder"/>
+        <module name="VariableDeclarationUsageDistance"/>
+        <module name="CustomImportOrder">
+            <property name="sortImportsInGroupAlphabetically" value="true"/>
+            <property name="separateLineBetweenGroups" value="true"/>
+            <property name="customImportOrderRules" value="STATIC###THIRD_PARTY_PACKAGE"/>
+            <property name="tokens" value="IMPORT, STATIC_IMPORT, PACKAGE_DEF"/>
+        </module>
+
+        <module name="MethodParamPad">
+            <property name="tokens"
+                      value="CTOR_DEF, LITERAL_NEW, METHOD_CALL, METHOD_DEF,
+                    SUPER_CTOR_CALL, ENUM_CONSTANT_DEF"/>
+        </module>
+
+        <module name="NoWhitespaceBefore">
+            <property name="tokens"
+                      value="COMMA, SEMI, POST_INC, POST_DEC, DOT, ELLIPSIS, METHOD_REF"/>
+            <property name="allowLineBreaks" value="true"/>
+        </module>
+
+        <module name="ParenPad">
+            <property name="tokens"
+                      value="ANNOTATION, ANNOTATION_FIELD_DEF, CTOR_CALL, CTOR_DEF, DOT, ENUM_CONSTANT_DEF,
+                    EXPR, LITERAL_CATCH, LITERAL_DO, LITERAL_FOR, LITERAL_IF, LITERAL_NEW,
+                    LITERAL_SWITCH, LITERAL_SYNCHRONIZED, LITERAL_WHILE, METHOD_CALL,
+                    METHOD_DEF, QUESTION, RESOURCE_SPECIFICATION, SUPER_CTOR_CALL, LAMBDA"/>
+        </module>
+
+        <module name="OperatorWrap">
+            <property name="option" value="NL"/>
+            <property name="tokens"
+                      value="BAND, BOR, BSR, BXOR, DIV, EQUAL, GE, GT, LAND, LE, LITERAL_INSTANCEOF, LOR,
+                    LT, MINUS, MOD, NOT_EQUAL, PLUS, QUESTION, SL, SR, STAR, METHOD_REF "/>
+        </module>
+
+        <module name="AnnotationLocation">
+            <property name="id" value="AnnotationLocationMostCases"/>
+            <property name="tokens"
+                      value="CLASS_DEF, INTERFACE_DEF, ENUM_DEF, METHOD_DEF, CTOR_DEF"/>
+        </module>
+
+        <module name="AnnotationLocation">
+            <property name="id" value="AnnotationLocationVariables"/>
+            <property name="tokens" value="VARIABLE_DEF"/>
+            <property name="allowSamelineMultipleAnnotations" value="true"/>
+        </module>
+
+        <module name="NonEmptyAtclauseDescription"/>
+        <module name="InvalidJavadocPosition"/>
+        <module name="JavadocTagContinuationIndentation"/>
+        <module name="SummaryJavadoc">
+            <property name="forbiddenSummaryFragments"
+                      value="^@return the *|^This method returns |^A [{]@code [a-zA-Z0-9]+[}]( is a )"/>
+        </module>
+
+        <module name="JavadocParagraph"/>
+        <module name="AtclauseOrder">
+            <property name="tagOrder" value="@param, @return, @throws, @deprecated"/>
+            <property name="target"
+                      value="CLASS_DEF, INTERFACE_DEF, ENUM_DEF, METHOD_DEF, CTOR_DEF, VARIABLE_DEF"/>
+        </module>
+
+        <module name="JavadocMethod">
+            <property name="scope" value="public"/>
+            <property name="allowMissingParamTags" value="true"/>
+            <property name="allowMissingReturnTag" value="true"/>
+            <property name="allowedAnnotations" value="Override, Test"/>
+            <property name="tokens" value="METHOD_DEF, CTOR_DEF, ANNOTATION_FIELD_DEF"/>
+        </module>
+
+        <module name="MissingJavadocMethod">
+            <property name="scope" value="public"/>
+            <property name="minLineCount" value="2"/>
+            <property name="allowedAnnotations" value="Override, Test, Start"/>
+            <property name="tokens" value="METHOD_DEF, CTOR_DEF, ANNOTATION_FIELD_DEF"/>
+        </module>
+
+        <module name="MethodName">
+            <property name="format" value="^[a-z][a-z0-9][a-zA-Z0-9_]*$"/>
+            <message key="name.invalidPattern"
+                     value="Method name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+
+        <module name="SingleLineJavadoc">
+            <property name="ignoreInlineTags" value="false"/>
+        </module>
+
+        <module name="EmptyCatchBlock">
+            <property name="exceptionVariableName" value="expected"/>
+        </module>
+
+        <module name="CommentsIndentation">
+            <property name="tokens" value="SINGLE_LINE_COMMENT, BLOCK_COMMENT_BEGIN"/>
+        </module>
+
+        <!-- https://checkstyle.org/config_filters.html#SuppressionXpathFilter -->
+        <module name="SuppressionXpathFilter">
+            <property name="file" value="${org.checkstyle.google.suppressionxpathfilter.config}"
+                      default="checkstyle-xpath-suppressions.xml" />
+            <property name="optional" value="true"/>
+        </module>
+
+    </module>
+
+</module>
+
diff --git a/gui/src/test/java/sigblockchain/projectred/gui/MultiplePaneTest.java b/gui/src/test/java/sigblockchain/projectred/gui/MultiplePaneTest.java
index 5a2f25e..cd45569 100644
--- a/gui/src/test/java/sigblockchain/projectred/gui/MultiplePaneTest.java
+++ b/gui/src/test/java/sigblockchain/projectred/gui/MultiplePaneTest.java
@@ -1,5 +1,8 @@
 package sigblockchain.projectred.gui;
 
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
 import javafx.fxml.FXMLLoader;
 import javafx.scene.Parent;
 import javafx.scene.Scene;
@@ -13,14 +16,10 @@
 import org.testfx.framework.junit5.Start;
 import org.testfx.matcher.control.LabeledMatchers;
 
-import static org.junit.jupiter.api.Assertions.assertFalse;
-import static org.junit.jupiter.api.Assertions.assertTrue;
-
 @ExtendWith(ApplicationExtension.class)
 
 public class MultiplePaneTest {
 
-
 	@Start
 	public void start(Stage stage) throws Exception {
 		Parent root = FXMLLoader.load(Main.class.getResource("scene.fxml"));
diff --git a/keys/src/main/java/sigblockchain/projectred/keys/KeyManager.java b/keys/src/main/java/sigblockchain/projectred/keys/KeyManager.java
index 06534a5..df2275a 100644
--- a/keys/src/main/java/sigblockchain/projectred/keys/KeyManager.java
+++ b/keys/src/main/java/sigblockchain/projectred/keys/KeyManager.java
@@ -1,6 +1,14 @@
 package sigblockchain.projectred.keys;
 
-import org.bouncycastle.asn1.*;
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.math.BigInteger;
+import java.security.SecureRandom;
+import org.bouncycastle.asn1.ASN1InputStream;
+import org.bouncycastle.asn1.ASN1Integer;
+import org.bouncycastle.asn1.ASN1Primitive;
+import org.bouncycastle.asn1.DERSequenceGenerator;
+import org.bouncycastle.asn1.DLSequence;
 import org.bouncycastle.asn1.sec.SECNamedCurves;
 import org.bouncycastle.asn1.x9.X9ECParameters;
 import org.bouncycastle.crypto.AsymmetricCipherKeyPair;
@@ -12,17 +20,12 @@
 import org.bouncycastle.crypto.signers.ECDSASigner;
 import org.bouncycastle.util.Properties;
 
-import java.io.ByteArrayOutputStream;
-import java.io.IOException;
-import java.math.BigInteger;
-import java.security.SecureRandom;
-
-
 public class KeyManager {
 
 	public static final X9ECParameters ecp = SECNamedCurves.getByName("secp256r1");
 	public static final ECDomainParameters domainParams = new ECDomainParameters(ecp.getCurve(),
-			ecp.getG(), ecp.getN(), ecp.getH(), ecp.getSeed());
+		ecp.getG(), ecp.getN(), ecp.getH(), ecp.getSeed());
+
 
 	/**
 	 * Will generate a public/private key pair according to the NIST P-256 standards.
@@ -30,8 +33,8 @@ public class KeyManager {
 	 * @return a AsymmetricCipherKeyPair object
 	 */
 	public static AsymmetricCipherKeyPair generateKeyPair() {
-		ECKeyGenerationParameters keyGenParams = new ECKeyGenerationParameters(domainParams, new SecureRandom());
-		ECKeyPairGenerator generator = new ECKeyPairGenerator();
+		var keyGenParams = new ECKeyGenerationParameters(domainParams, new SecureRandom());
+		var generator = new ECKeyPairGenerator();
 		generator.init(keyGenParams);
 		return generator.generateKeyPair();
 	}
@@ -65,21 +68,22 @@ public static byte[] sign(ECPrivateKeyParameters privateKey, byte[] data)   {
 	 */
 	public static boolean verify(ECPublicKeyParameters publicKey, byte[] signature, byte[] data) {
 
-		BigInteger[] rAndS = decodeDerSignature(signature);
-		if (rAndS == null)
+		BigInteger[] randS = decodeDerSignature(signature);
+		if (randS == null) {
 			return false;
-		var r = rAndS[0];
-		var s = rAndS[1];
+		}
+		var r = randS[0];
+		var s = randS[1];
 
 		ECDSASigner signer = new ECDSASigner();
 		signer.init(false, publicKey);
-
-		 return signer.verifySignature(data, r, s);
+		return signer.verifySignature(data, r, s);
 	}
 
-	private static BigInteger[] decodeDerSignature(byte[] signature){
+	private static BigInteger[] decodeDerSignature(byte[] signature) {
 		//first we have to decode the the DER encoded byte array
-		BigInteger r, s;
+		BigInteger r;
+		BigInteger s;
 		ASN1InputStream decoder = null;
 		try {
 			// BouncyCastle by default is strict about parsing ASN.1 integers.
diff --git a/keys/src/test/java/sigblockchain/projectred/keys/KeyManagerTest.java b/keys/src/test/java/sigblockchain/projectred/keys/KeyManagerTest.java
index 7e859bf..0478b00 100644
--- a/keys/src/test/java/sigblockchain/projectred/keys/KeyManagerTest.java
+++ b/keys/src/test/java/sigblockchain/projectred/keys/KeyManagerTest.java
@@ -4,7 +4,6 @@
 import static org.junit.jupiter.api.Assertions.assertFalse;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
-
 import java.math.BigInteger;
 import org.bouncycastle.crypto.params.ECPrivateKeyParameters;
 import org.bouncycastle.crypto.params.ECPublicKeyParameters;
@@ -13,23 +12,8 @@
 import org.bouncycastle.util.encoders.Hex;
 import org.junit.jupiter.api.Test;
 
-
 class KeyManagerTest {
 
-	@Test
-	public void testGenerateKeyPair() {
-		var keyPair = KeyManager.generateKeyPair();
-		var privateKey = (ECPrivateKeyParameters) keyPair.getPrivate();
-		var actualPublicKey = (ECPublicKeyParameters) keyPair.getPublic();
-
-		ECPoint Q = KeyManager.domainParams.getG().multiply(privateKey.getD());
-		var expectedPublicKey = new ECPublicKeyParameters(Q, KeyManager.domainParams);
-		assertEquals(actualPublicKey.getQ().getRawXCoord().toBigInteger(), expectedPublicKey.getQ().getRawXCoord().toBigInteger());
-		assertEquals(actualPublicKey.getQ().getRawYCoord().toBigInteger(), expectedPublicKey.getQ().getRawYCoord().toBigInteger());
-
-	}
-
-
 	@Test
 	public void testEcParameters() {
 		// an example of the P-256 public private key pair.
@@ -38,17 +22,30 @@ public void testEcParameters() {
 		var expectedPublicKeyY = new BigInteger("a797eb07a5d8eef80d5705a7a627c73cf4e683ab98c7245101025be935c4053b", 16);
 
 		var fpMultiplier = new FixedPointCombMultiplier();
-		ECPoint Q = fpMultiplier.multiply(KeyManager.domainParams.getG(), expectedPrivateKey);
+		ECPoint q = fpMultiplier.multiply(KeyManager.domainParams.getG(), expectedPrivateKey);
 
-		var actualPublicKey = new ECPublicKeyParameters(Q, KeyManager.domainParams);
+		var actualPublicKey = new ECPublicKeyParameters(q, KeyManager.domainParams);
 		var actualPrivateKey = new ECPrivateKeyParameters(expectedPrivateKey, KeyManager.domainParams);
 
 		assertEquals(actualPrivateKey.getD(), expectedPrivateKey);
 		assertEquals(actualPublicKey.getQ().getRawXCoord().toBigInteger(), expectedPublicKeyX);
 		assertEquals(actualPublicKey.getQ().getRawYCoord().toBigInteger(), expectedPublicKeyY);
-
 	}
 
+	@Test
+	public void testGenerateKeyPair() {
+		var keyPair = KeyManager.generateKeyPair();
+		var privateKey = (ECPrivateKeyParameters) keyPair.getPrivate();
+		var actualPublicKey = (ECPublicKeyParameters) keyPair.getPublic();
+
+		ECPoint q = KeyManager.domainParams.getG().multiply(privateKey.getD());
+		var expectedPublicKey = new ECPublicKeyParameters(q, KeyManager.domainParams);
+		assertEquals(actualPublicKey.getQ().getRawXCoord().toBigInteger(),
+			expectedPublicKey.getQ().getRawXCoord().toBigInteger());
+		assertEquals(actualPublicKey.getQ().getRawYCoord().toBigInteger(),
+			expectedPublicKey.getQ().getRawYCoord().toBigInteger());
+
+	}
 
 	@Test
 	public void testSigning1() {
@@ -63,8 +60,12 @@ public void testSigning1() {
 
 	@Test
 	public void testSigning2() {
-		var signature = Hex.decode("3045022100ff2c146535e75f0b5c8fb3548077f799429f72b4eb2e5412e89678b29fb165e3022036332b243d0f28fd05e9dca1be6eb1ff577622148e245732951fdfb71a4e684b");
-		var fakeSignature = Hex.decode("1045022100ff2c146535e75f0b5c8fb3548077f799429f72b4eb2e5412e89678b29fb165e3022036332b243d0f28fd05e9dca1be6eb1ff577622148e245732951fdfb71a4e684b");
+		var signature = Hex.decode(
+			"3045022100ff2c146535e75f0b5c8fb3548077f799429f72b4eb2e5412e89678b29fb16"
+				+ "5e3022036332b243d0f28fd05e9dca1be6eb1ff577622148e245732951fdfb71a4e684b");
+		var fakeSignature = Hex.decode(
+			"1045022100ff2c146535e75f0b5c8fb3548077f799429f72b4eb2e5412e89678b29fb16"
+				+ "5e3022036332b243d0f28fd05e9dca1be6eb1ff577622148e245732951fdfb71a4e684b");
 
 		var data = "Data".getBytes();
 		var privateKeyNum = new BigInteger("d8353db7fe564c633f94274d7bc1d7200740e3ac5b617dc1f438feecfebec562", 16);
@@ -77,5 +78,4 @@ public void testSigning2() {
 		assertFalse(KeyManager.verify(constructedPrivateKey, fakeSignature, data));
 
 	}
-
 }