--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/main/java/christie/blockchain/BlockHeader.java	Mon Nov 05 10:16:28 2018 +0900
@@ -0,0 +1,81 @@
+package christie.blockchain;
+
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.math.BigInteger;
+import java.nio.charset.Charset;
+
+public class BlockHeader {
+
+    private byte[] presentHash;
+
+    private byte[] parentHash;
+
+    private long timestamp;
+
+    private long nonce;
+
+    public BlockHeader(byte[] parentHash, long timestamp) {
+        this.parentHash = parentHash;
+        this.timestamp = timestamp;
+        this.presentHash = calcHash();
+    }
+
+    public byte[] calcHash(){
+        HashUtil hashUtil = new HashUtil();
+
+        byte[] timestampByte = BigInteger.valueOf(this.timestamp).toByteArray();
+
+        byte[] nonceByte = BigInteger.valueOf(this.nonce).toByteArray();
+
+        ByteArrayOutputStream output = new ByteArrayOutputStream();
+
+        try {
+            output.write(parentHash);
+            output.write(timestampByte);
+            output.write(nonceByte);
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+
+        return hashUtil.sha256(output.toByteArray());
+
+    }
+
+    public byte[] getParentHash() {
+        return parentHash;
+    }
+
+    public byte[] getPresentHash() {
+        if(this.presentHash == null){
+            this.presentHash = calcHash();
+        }
+        return this.presentHash;
+    }
+
+
+    public long getTimestamp() {
+        return timestamp;
+    }
+
+    public void setTimestamp(long timestamp) {
+        this.timestamp = timestamp;
+    }
+
+    public void mineBlock(int difficulty) {
+        String target = new String(new char[difficulty]).replace('\0', '0');
+        String hashStr = new String(presentHash, Charset.forName("utf-16"));
+
+        while(!hashStr.substring( 0, difficulty).equals(target)) {
+            this.nonce ++;
+            this.presentHash = calcHash();
+            hashStr = new String(this.presentHash, Charset.forName("utf-16"));
+        }
+        System.out.println("Block Mined!!! : " + hashStr);
+    }
+
+    public long getNonce(){
+        return this.nonce;
+    }
+
+}