diff --git a/consensus/ibft/src/main/java/tech/pegasys/pantheon/consensus/ibft/Ibft2ExtraData.java b/consensus/ibft/src/main/java/tech/pegasys/pantheon/consensus/ibft/Ibft2ExtraData.java
new file mode 100644
index 0000000000..e80891b75e
--- /dev/null
+++ b/consensus/ibft/src/main/java/tech/pegasys/pantheon/consensus/ibft/Ibft2ExtraData.java
@@ -0,0 +1,121 @@
+/*
+ * Copyright 2018 ConsenSys AG.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
+ * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations under the License.
+ */
+package tech.pegasys.pantheon.consensus.ibft;
+
+import static com.google.common.base.Preconditions.checkArgument;
+import static com.google.common.base.Preconditions.checkNotNull;
+
+import tech.pegasys.pantheon.crypto.SECP256K1.Signature;
+import tech.pegasys.pantheon.ethereum.core.Address;
+import tech.pegasys.pantheon.ethereum.rlp.BytesValueRLPInput;
+import tech.pegasys.pantheon.ethereum.rlp.BytesValueRLPOutput;
+import tech.pegasys.pantheon.ethereum.rlp.RLPInput;
+import tech.pegasys.pantheon.util.bytes.BytesValue;
+
+import java.util.List;
+import java.util.Optional;
+
+/**
+ * Represents the data structure stored in the extraData field of the BlockHeader used when
+ * operating under an IBFT 2.0 consensus mechanism.
+ */
+public class Ibft2ExtraData {
+
+  public static final int EXTRA_VANITY_LENGTH = 32;
+
+  private final BytesValue vanityData;
+  private final List<Signature> seals;
+  private final Optional<Vote> vote;
+  private final int round;
+  private final List<Address> validators;
+
+  public Ibft2ExtraData(
+      final BytesValue vanityData,
+      final List<Signature> seals,
+      final Optional<Vote> vote,
+      final int round,
+      final List<Address> validators) {
+
+    checkNotNull(vanityData);
+    checkNotNull(seals);
+    checkNotNull(validators);
+
+    this.vanityData = vanityData;
+    this.seals = seals;
+    this.round = round;
+    this.validators = validators;
+    this.vote = vote;
+  }
+
+  public static Ibft2ExtraData decode(final BytesValue input) {
+    checkArgument(
+        input.size() > EXTRA_VANITY_LENGTH,
+        "Invalid BytesValue supplied - too short to produce a valid IBFT Extra Data object.");
+
+    final RLPInput rlpInput = new BytesValueRLPInput(input, false);
+
+    rlpInput.enterList(); // This accounts for the "root node" which contains IBFT data items.
+    final BytesValue vanityData = rlpInput.readBytesValue();
+    final List<Address> validators = rlpInput.readList(Address::readFrom);
+    final Optional<Vote> vote;
+    if (rlpInput.nextIsNull()) {
+      vote = Optional.empty();
+      rlpInput.skipNext();
+    } else {
+      vote = Optional.of(Vote.readFrom(rlpInput));
+    }
+    final int round = rlpInput.readInt();
+    final List<Signature> seals = rlpInput.readList(rlp -> Signature.decode(rlp.readBytesValue()));
+    rlpInput.leaveList();
+
+    return new Ibft2ExtraData(vanityData, seals, vote, round, validators);
+  }
+
+  public BytesValue encode() {
+    final BytesValueRLPOutput encoder = new BytesValueRLPOutput();
+    encoder.startList();
+    encoder.writeBytesValue(vanityData);
+    encoder.writeList(validators, (validator, rlp) -> rlp.writeBytesValue(validator));
+    if (vote.isPresent()) {
+      vote.get().writeTo(encoder);
+    } else {
+      encoder.writeNull();
+    }
+    encoder.writeInt(round);
+    encoder.writeList(seals, (committer, rlp) -> rlp.writeBytesValue(committer.encodedBytes()));
+    encoder.endList();
+
+    return encoder.encoded();
+  }
+
+  // Accessors
+  public BytesValue getVanityData() {
+    return vanityData;
+  }
+
+  public List<Signature> getSeals() {
+    return seals;
+  }
+
+  public List<Address> getValidators() {
+    return validators;
+  }
+
+  public Optional<Vote> getVote() {
+    return vote;
+  }
+
+  public int getRound() {
+    return round;
+  }
+}
diff --git a/consensus/ibft/src/main/java/tech/pegasys/pantheon/consensus/ibft/Ibft2VoteType.java b/consensus/ibft/src/main/java/tech/pegasys/pantheon/consensus/ibft/Ibft2VoteType.java
new file mode 100644
index 0000000000..d505679abe
--- /dev/null
+++ b/consensus/ibft/src/main/java/tech/pegasys/pantheon/consensus/ibft/Ibft2VoteType.java
@@ -0,0 +1,47 @@
+/*
+ * Copyright 2018 ConsenSys AG.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
+ * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations under the License.
+ */
+package tech.pegasys.pantheon.consensus.ibft;
+
+import tech.pegasys.pantheon.ethereum.rlp.RLPException;
+import tech.pegasys.pantheon.ethereum.rlp.RLPInput;
+import tech.pegasys.pantheon.ethereum.rlp.RLPOutput;
+
+public enum Ibft2VoteType {
+  ADD((byte) 0xFF),
+  DROP((byte) 0x00);
+
+  private final byte voteValue;
+
+  Ibft2VoteType(final byte voteValue) {
+    this.voteValue = voteValue;
+  }
+
+  public byte getVoteValue() {
+    return voteValue;
+  }
+
+  public static Ibft2VoteType readFrom(final RLPInput rlpInput) {
+    byte encodedByteValue = rlpInput.readByte();
+    for (final Ibft2VoteType voteType : values()) {
+      if (voteType.voteValue == encodedByteValue) {
+        return voteType;
+      }
+    }
+
+    throw new RLPException("Invalid Ibft2VoteType RLP encoding");
+  }
+
+  public void writeTo(final RLPOutput rlpOutput) {
+    rlpOutput.writeByte(voteValue);
+  }
+}
diff --git a/consensus/ibft/src/main/java/tech/pegasys/pantheon/consensus/ibft/Vote.java b/consensus/ibft/src/main/java/tech/pegasys/pantheon/consensus/ibft/Vote.java
new file mode 100644
index 0000000000..0faf37aa01
--- /dev/null
+++ b/consensus/ibft/src/main/java/tech/pegasys/pantheon/consensus/ibft/Vote.java
@@ -0,0 +1,87 @@
+/*
+ * Copyright 2018 ConsenSys AG.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
+ * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations under the License.
+ */
+package tech.pegasys.pantheon.consensus.ibft;
+
+import tech.pegasys.pantheon.ethereum.core.Address;
+import tech.pegasys.pantheon.ethereum.rlp.RLPInput;
+import tech.pegasys.pantheon.ethereum.rlp.RLPOutput;
+
+import com.google.common.base.Objects;
+
+public class Vote {
+  private final Address recipient;
+  private final Ibft2VoteType voteType;
+
+  private Vote(final Address recipient, final Ibft2VoteType voteType) {
+    this.recipient = recipient;
+    this.voteType = voteType;
+  }
+
+  public static Vote authVote(final Address address) {
+    return new Vote(address, Ibft2VoteType.ADD);
+  }
+
+  public static Vote dropVote(final Address address) {
+    return new Vote(address, Ibft2VoteType.DROP);
+  }
+
+  public Address getRecipient() {
+    return recipient;
+  }
+
+  public boolean isAuth() {
+    return voteType.equals(Ibft2VoteType.ADD);
+  }
+
+  public boolean isDrop() {
+    return voteType.equals(Ibft2VoteType.DROP);
+  }
+
+  @Override
+  public boolean equals(final Object o) {
+    if (this == o) {
+      return true;
+    }
+    if (o == null || getClass() != o.getClass()) {
+      return false;
+    }
+    final Vote vote1 = (Vote) o;
+    return recipient.equals(vote1.recipient) && voteType.equals(vote1.voteType);
+  }
+
+  @Override
+  public int hashCode() {
+    return Objects.hashCode(recipient, voteType);
+  }
+
+  public Ibft2VoteType getVoteType() {
+    return voteType;
+  }
+
+  public void writeTo(final RLPOutput rlpOutput) {
+    rlpOutput.startList();
+    rlpOutput.writeBytesValue(recipient);
+    voteType.writeTo(rlpOutput);
+    rlpOutput.endList();
+  }
+
+  public static Vote readFrom(final RLPInput rlpInput) {
+
+    rlpInput.enterList();
+    final Address recipient = Address.readFrom(rlpInput);
+    final Ibft2VoteType vote = Ibft2VoteType.readFrom(rlpInput);
+    rlpInput.leaveList();
+
+    return new Vote(recipient, vote);
+  }
+}
diff --git a/consensus/ibft/src/test/java/tech/pegasys/pantheon/consensus/ibft/Ibft2ExtraDataTest.java b/consensus/ibft/src/test/java/tech/pegasys/pantheon/consensus/ibft/Ibft2ExtraDataTest.java
new file mode 100644
index 0000000000..4aa801039c
--- /dev/null
+++ b/consensus/ibft/src/test/java/tech/pegasys/pantheon/consensus/ibft/Ibft2ExtraDataTest.java
@@ -0,0 +1,415 @@
+/*
+ * Copyright 2018 ConsenSys AG.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
+ * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations under the License.
+ */
+package tech.pegasys.pantheon.consensus.ibft;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+
+import tech.pegasys.pantheon.crypto.SECP256K1.Signature;
+import tech.pegasys.pantheon.ethereum.core.Address;
+import tech.pegasys.pantheon.ethereum.rlp.BytesValueRLPOutput;
+import tech.pegasys.pantheon.ethereum.rlp.RLPException;
+import tech.pegasys.pantheon.ethereum.rlp.RLPInput;
+import tech.pegasys.pantheon.util.bytes.BytesValue;
+
+import java.math.BigInteger;
+import java.util.Arrays;
+import java.util.List;
+import java.util.Optional;
+import java.util.Random;
+
+import com.google.common.collect.Lists;
+import org.junit.Test;
+
+public class Ibft2ExtraDataTest {
+  private final String RAW_HEX_ENCODING_STRING =
+      "f8f1a00102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f20ea9400000000000000000000000000000000000"
+          + "00001940000000000000000000000000000000000000002d794000000000000000000000000000000000000000181ff8400fedc"
+          + "baf886b841000000000000000000000000000000000000000000000000000000000000000100000000000000000000000000000"
+          + "0000000000000000000000000000000000a00b84100000000000000000000000000000000000000000000000000000000000000"
+          + "0a000000000000000000000000000000000000000000000000000000000000000100";
+
+  private final Ibft2ExtraData DECODED_EXTRA_DATA_FOR_RAW_HEX_ENCODING_STRING =
+      getDecodedExtraDataForRawHexEncodingString();
+
+  private static Ibft2ExtraData getDecodedExtraDataForRawHexEncodingString() {
+    final List<Address> validators =
+        Arrays.asList(Address.fromHexString("1"), Address.fromHexString("2"));
+    final Optional<Vote> vote = Optional.of(Vote.authVote(Address.fromHexString("1")));
+    final int round = 0x00FEDCBA;
+    final List<Signature> committerSeals =
+        Arrays.asList(
+            Signature.create(BigInteger.ONE, BigInteger.TEN, (byte) 0),
+            Signature.create(BigInteger.TEN, BigInteger.ONE, (byte) 0));
+
+    // Create a byte buffer with no data.
+    final byte[] vanity_bytes = createNonEmptyVanityData();
+    final BytesValue vanity_data = BytesValue.wrap(vanity_bytes);
+
+    return new Ibft2ExtraData(vanity_data, committerSeals, vote, round, validators);
+  }
+
+  @Test
+  public void correctlyCodedRoundConstitutesValidContent() {
+    final List<Address> validators = Lists.newArrayList();
+    final Optional<Vote> vote = Optional.of(Vote.authVote(Address.fromHexString("1")));
+    final int round = 0x00FEDCBA;
+    final byte[] roundAsByteArray = new byte[] {(byte) 0x00, (byte) 0xFE, (byte) 0xDC, (byte) 0xBA};
+    final List<Signature> committerSeals = Lists.newArrayList();
+
+    // Create a byte buffer with no data.
+    final byte[] vanity_bytes = new byte[32];
+    final BytesValue vanity_data = BytesValue.wrap(vanity_bytes);
+
+    final BytesValueRLPOutput encoder = new BytesValueRLPOutput();
+    encoder.startList();
+    encoder.writeBytesValue(vanity_data);
+    encoder.writeList(validators, (validator, rlp) -> rlp.writeBytesValue(validator));
+
+    // encoded vote
+    encoder.startList();
+    encoder.writeBytesValue(vote.get().getRecipient());
+    vote.get().getVoteType().writeTo(encoder);
+    encoder.endList();
+
+    // This is to verify that the decoding works correctly when the round is encoded as 4 bytes
+    encoder.writeBytesValue(BytesValue.wrap(roundAsByteArray));
+    encoder.writeList(
+        committerSeals, (committer, rlp) -> rlp.writeBytesValue(committer.encodedBytes()));
+    encoder.endList();
+
+    final BytesValue bufferToInject = encoder.encoded();
+
+    final Ibft2ExtraData extraData = Ibft2ExtraData.decode(bufferToInject);
+
+    assertThat(extraData.getVanityData()).isEqualTo(vanity_data);
+    assertThat(extraData.getVote()).isEqualTo(vote);
+    assertThat(extraData.getRound()).isEqualTo(round);
+    assertThat(extraData.getSeals()).isEqualTo(committerSeals);
+    assertThat(extraData.getValidators()).isEqualTo(validators);
+  }
+
+  /**
+   * This test specifically verifies that {@link Ibft2ExtraData#decode(BytesValue)} uses {@link
+   * RLPInput#readInt()} rather than {@link RLPInput#readIntScalar()} to decode the round number
+   */
+  @Test
+  public void incorrectlyEncodedRoundThrowsRlpException() {
+    final List<Address> validators = Lists.newArrayList();
+    final Optional<Vote> vote = Optional.of(Vote.authVote(Address.fromHexString("1")));
+    final byte[] roundAsByteArray = new byte[] {(byte) 0xFE, (byte) 0xDC, (byte) 0xBA};
+    final List<Signature> committerSeals = Lists.newArrayList();
+
+    // Create a byte buffer with no data.
+    final byte[] vanity_bytes = new byte[32];
+    final BytesValue vanity_data = BytesValue.wrap(vanity_bytes);
+
+    final BytesValueRLPOutput encoder = new BytesValueRLPOutput();
+    encoder.startList();
+    encoder.writeBytesValue(vanity_data);
+    encoder.writeList(validators, (validator, rlp) -> rlp.writeBytesValue(validator));
+
+    // encoded vote
+    encoder.startList();
+    encoder.writeBytesValue(vote.get().getRecipient());
+    vote.get().getVoteType().writeTo(encoder);
+    encoder.endList();
+
+    // This is to verify that the decoding throws an exception when the round number is not encoded
+    // in 4 byte format
+    encoder.writeBytesValue(BytesValue.wrap(roundAsByteArray));
+    encoder.writeList(
+        committerSeals, (committer, rlp) -> rlp.writeBytesValue(committer.encodedBytes()));
+    encoder.endList();
+
+    final BytesValue bufferToInject = encoder.encoded();
+
+    assertThatThrownBy(() -> Ibft2ExtraData.decode(bufferToInject))
+        .isInstanceOf(RLPException.class);
+  }
+
+  @Test
+  public void nullVoteAndListConstituteValidContent() {
+    final List<Address> validators = Lists.newArrayList();
+    final int round = 0x00FEDCBA;
+    final List<Signature> committerSeals = Lists.newArrayList();
+
+    // Create a byte buffer with no data.
+    final byte[] vanity_bytes = new byte[32];
+    final BytesValue vanity_data = BytesValue.wrap(vanity_bytes);
+
+    final BytesValueRLPOutput encoder = new BytesValueRLPOutput();
+    encoder.startList();
+    encoder.writeBytesValue(vanity_data);
+    encoder.writeList(validators, (validator, rlp) -> rlp.writeBytesValue(validator));
+
+    // encode an empty vote
+    encoder.writeNull();
+
+    encoder.writeInt(round);
+    encoder.writeList(
+        committerSeals, (committer, rlp) -> rlp.writeBytesValue(committer.encodedBytes()));
+    encoder.endList();
+
+    final BytesValue bufferToInject = encoder.encoded();
+
+    final Ibft2ExtraData extraData = Ibft2ExtraData.decode(bufferToInject);
+
+    assertThat(extraData.getVanityData()).isEqualTo(vanity_data);
+    assertThat(extraData.getVote().isPresent()).isEqualTo(false);
+    assertThat(extraData.getRound()).isEqualTo(round);
+    assertThat(extraData.getSeals()).isEqualTo(committerSeals);
+    assertThat(extraData.getValidators()).isEqualTo(validators);
+  }
+
+  @Test
+  public void emptyVoteAndListIsEncodedCorrectly() {
+    final List<Address> validators = Lists.newArrayList();
+    Optional<Vote> vote = Optional.empty();
+    final int round = 0x00FEDCBA;
+    final List<Signature> committerSeals = Lists.newArrayList();
+
+    // Create a byte buffer with no data.
+    final byte[] vanity_bytes = new byte[32];
+    final BytesValue vanity_data = BytesValue.wrap(vanity_bytes);
+
+    Ibft2ExtraData expectedExtraData =
+        new Ibft2ExtraData(vanity_data, committerSeals, vote, round, validators);
+
+    Ibft2ExtraData actualExtraData = Ibft2ExtraData.decode(expectedExtraData.encode());
+
+    assertThat(actualExtraData).isEqualToComparingFieldByField(expectedExtraData);
+  }
+
+  @Test
+  public void emptyListConstituteValidContent() {
+    final List<Address> validators = Lists.newArrayList();
+    final Optional<Vote> vote = Optional.of(Vote.dropVote(Address.fromHexString("1")));
+    final int round = 0x00FEDCBA;
+    final List<Signature> committerSeals = Lists.newArrayList();
+
+    // Create a byte buffer with no data.
+    final byte[] vanity_bytes = new byte[32];
+    final BytesValue vanity_data = BytesValue.wrap(vanity_bytes);
+
+    final BytesValueRLPOutput encoder = new BytesValueRLPOutput();
+    encoder.startList();
+    encoder.writeBytesValue(vanity_data);
+    encoder.writeList(validators, (validator, rlp) -> rlp.writeBytesValue(validator));
+
+    // encoded vote
+    encoder.startList();
+    encoder.writeBytesValue(vote.get().getRecipient());
+    vote.get().getVoteType().writeTo(encoder);
+    encoder.endList();
+
+    encoder.writeInt(round);
+    encoder.writeList(
+        committerSeals, (committer, rlp) -> rlp.writeBytesValue(committer.encodedBytes()));
+    encoder.endList();
+
+    final BytesValue bufferToInject = encoder.encoded();
+
+    final Ibft2ExtraData extraData = Ibft2ExtraData.decode(bufferToInject);
+
+    assertThat(extraData.getVanityData()).isEqualTo(vanity_data);
+    assertThat(extraData.getVote()).isEqualTo(vote);
+    assertThat(extraData.getRound()).isEqualTo(round);
+    assertThat(extraData.getSeals()).isEqualTo(committerSeals);
+    assertThat(extraData.getValidators()).isEqualTo(validators);
+  }
+
+  @Test
+  public void emptyListsAreEncodedAndDecodedCorrectly() {
+    final List<Address> validators = Lists.newArrayList();
+    final Optional<Vote> vote = Optional.of(Vote.authVote(Address.fromHexString("1")));
+    final int round = 0x00FEDCBA;
+    final List<Signature> committerSeals = Lists.newArrayList();
+
+    // Create a byte buffer with no data.
+    final byte[] vanity_bytes = new byte[32];
+    final BytesValue vanity_data = BytesValue.wrap(vanity_bytes);
+
+    Ibft2ExtraData expectedExtraData =
+        new Ibft2ExtraData(vanity_data, committerSeals, vote, round, validators);
+
+    Ibft2ExtraData actualExtraData = Ibft2ExtraData.decode(expectedExtraData.encode());
+
+    assertThat(actualExtraData).isEqualToComparingFieldByField(expectedExtraData);
+  }
+
+  @Test
+  public void fullyPopulatedDataProducesCorrectlyFormedExtraDataObject() {
+    final List<Address> validators =
+        Arrays.asList(Address.fromHexString("1"), Address.fromHexString("2"));
+    final Optional<Vote> vote = Optional.of(Vote.authVote(Address.fromHexString("1")));
+    final int round = 0x00FEDCBA;
+    final List<Signature> committerSeals =
+        Arrays.asList(
+            Signature.create(BigInteger.ONE, BigInteger.TEN, (byte) 0),
+            Signature.create(BigInteger.TEN, BigInteger.ONE, (byte) 0));
+
+    // Create randomised vanity data.
+    final byte[] vanity_bytes = createNonEmptyVanityData();
+    new Random().nextBytes(vanity_bytes);
+    final BytesValue vanity_data = BytesValue.wrap(vanity_bytes);
+
+    final BytesValueRLPOutput encoder = new BytesValueRLPOutput();
+    encoder.startList(); // This is required to create a "root node" for all RLP'd data
+    encoder.writeBytesValue(vanity_data);
+    encoder.writeList(validators, (validator, rlp) -> rlp.writeBytesValue(validator));
+
+    // encoded vote
+    encoder.startList();
+    encoder.writeBytesValue(vote.get().getRecipient());
+    vote.get().getVoteType().writeTo(encoder);
+    encoder.endList();
+
+    encoder.writeInt(round);
+    encoder.writeList(
+        committerSeals, (committer, rlp) -> rlp.writeBytesValue(committer.encodedBytes()));
+    encoder.endList();
+
+    final BytesValue bufferToInject = encoder.encoded();
+
+    final Ibft2ExtraData extraData = Ibft2ExtraData.decode(bufferToInject);
+
+    assertThat(extraData.getVanityData()).isEqualTo(vanity_data);
+    assertThat(extraData.getVote()).isEqualTo(vote);
+    assertThat(extraData.getRound()).isEqualTo(round);
+    assertThat(extraData.getSeals()).isEqualTo(committerSeals);
+    assertThat(extraData.getValidators()).isEqualTo(validators);
+  }
+
+  @Test
+  public void fullyPopulatedDataIsEncodedAndDecodedCorrectly() {
+    final List<Address> validators =
+        Arrays.asList(Address.fromHexString("1"), Address.fromHexString("2"));
+    final Optional<Vote> vote = Optional.of(Vote.authVote(Address.fromHexString("1")));
+    final int round = 0x00FEDCBA;
+    final List<Signature> committerSeals =
+        Arrays.asList(
+            Signature.create(BigInteger.ONE, BigInteger.TEN, (byte) 0),
+            Signature.create(BigInteger.TEN, BigInteger.ONE, (byte) 0));
+
+    // Create a byte buffer with no data.
+    final byte[] vanity_bytes = createNonEmptyVanityData();
+    final BytesValue vanity_data = BytesValue.wrap(vanity_bytes);
+
+    Ibft2ExtraData expectedExtraData =
+        new Ibft2ExtraData(vanity_data, committerSeals, vote, round, validators);
+
+    Ibft2ExtraData actualExtraData = Ibft2ExtraData.decode(expectedExtraData.encode());
+
+    assertThat(actualExtraData).isEqualToComparingFieldByField(expectedExtraData);
+  }
+
+  @Test
+  public void encodingMatchesKnownRawHexString() {
+    BytesValue expectedRawDecoding = BytesValue.fromHexString(RAW_HEX_ENCODING_STRING);
+    assertThat(DECODED_EXTRA_DATA_FOR_RAW_HEX_ENCODING_STRING.encode())
+        .isEqualTo(expectedRawDecoding);
+  }
+
+  @Test
+  public void decodingOfKnownRawHexStringMatchesKnowExtraDataObject() {
+
+    final Ibft2ExtraData expectedExtraData = DECODED_EXTRA_DATA_FOR_RAW_HEX_ENCODING_STRING;
+
+    BytesValue rawDecoding = BytesValue.fromHexString(RAW_HEX_ENCODING_STRING);
+    Ibft2ExtraData actualExtraData = Ibft2ExtraData.decode(rawDecoding);
+
+    assertThat(actualExtraData).isEqualToComparingFieldByField(expectedExtraData);
+  }
+
+  @Test
+  public void incorrectlyStructuredRlpThrowsException() {
+    final List<Address> validators = Lists.newArrayList();
+    final Optional<Vote> vote = Optional.of(Vote.authVote(Address.fromHexString("1")));
+    final int round = 0x00FEDCBA;
+    final List<Signature> committerSeals = Lists.newArrayList();
+
+    // Create a byte buffer with no data.
+    final byte[] vanity_bytes = new byte[32];
+    final BytesValue vanity_data = BytesValue.wrap(vanity_bytes);
+
+    final BytesValueRLPOutput encoder = new BytesValueRLPOutput();
+    encoder.startList();
+    encoder.writeBytesValue(vanity_data);
+    encoder.writeList(validators, (validator, rlp) -> rlp.writeBytesValue(validator));
+
+    // encoded vote
+    encoder.startList();
+    encoder.writeBytesValue(vote.get().getRecipient());
+    vote.get().getVoteType().writeTo(encoder);
+    encoder.endList();
+
+    encoder.writeInt(round);
+    encoder.writeList(
+        committerSeals, (committer, rlp) -> rlp.writeBytesValue(committer.encodedBytes()));
+    encoder.writeLong(1);
+    encoder.endList();
+
+    final BytesValue bufferToInject = encoder.encoded();
+
+    assertThatThrownBy(() -> Ibft2ExtraData.decode(bufferToInject))
+        .isInstanceOf(RLPException.class);
+  }
+
+  @Test
+  public void incorrectVoteTypeThrowsException() {
+    final List<Address> validators =
+        Arrays.asList(Address.fromHexString("1"), Address.fromHexString("2"));
+    final Address voteRecipient = Address.fromHexString("1");
+    final byte voteType = (byte) 0xAA;
+    final int round = 0x00FEDCBA;
+    final List<Signature> committerSeals =
+        Arrays.asList(
+            Signature.create(BigInteger.ONE, BigInteger.TEN, (byte) 0),
+            Signature.create(BigInteger.TEN, BigInteger.ONE, (byte) 0));
+
+    // Create a byte buffer with no data.
+    final byte[] vanity_bytes = new byte[32];
+    final BytesValue vanity_data = BytesValue.wrap(vanity_bytes);
+
+    final BytesValueRLPOutput encoder = new BytesValueRLPOutput();
+    encoder.startList();
+    encoder.writeBytesValue(vanity_data);
+    encoder.writeList(validators, (validator, rlp) -> rlp.writeBytesValue(validator));
+
+    // encode vote
+    encoder.startList();
+    encoder.writeBytesValue(voteRecipient);
+    encoder.writeByte(voteType);
+    encoder.endList();
+
+    encoder.writeInt(round);
+    encoder.writeList(
+        committerSeals, (committer, rlp) -> rlp.writeBytesValue(committer.encodedBytes()));
+    encoder.endList();
+
+    final BytesValue bufferToInject = encoder.encoded();
+
+    assertThatThrownBy(() -> Ibft2ExtraData.decode(bufferToInject))
+        .isInstanceOf(RLPException.class);
+  }
+
+  private static byte[] createNonEmptyVanityData() {
+    final byte[] vanity_bytes = new byte[32];
+    for (int i = 0; i < vanity_bytes.length; i++) {
+      vanity_bytes[i] = (byte) (i + 1);
+    }
+
+    return vanity_bytes;
+  }
+}
diff --git a/consensus/ibft/src/test/java/tech/pegasys/pantheon/consensus/ibft/VoteTest.java b/consensus/ibft/src/test/java/tech/pegasys/pantheon/consensus/ibft/VoteTest.java
new file mode 100644
index 0000000000..81f297e86d
--- /dev/null
+++ b/consensus/ibft/src/test/java/tech/pegasys/pantheon/consensus/ibft/VoteTest.java
@@ -0,0 +1,30 @@
+/*
+ * Copyright 2018 ConsenSys AG.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
+ * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations under the License.
+ */
+package tech.pegasys.pantheon.consensus.ibft;
+
+import static org.assertj.core.api.Java6Assertions.assertThat;
+
+import tech.pegasys.pantheon.ethereum.core.Address;
+
+import org.junit.Test;
+
+public class VoteTest {
+  @Test
+  public void testStaticVoteCreationMethods() {
+    assertThat(Vote.authVote(Address.fromHexString("1")).isAuth()).isEqualTo(true);
+    assertThat(Vote.authVote(Address.fromHexString("1")).isDrop()).isEqualTo(false);
+
+    assertThat(Vote.dropVote(Address.fromHexString("1")).isAuth()).isEqualTo(false);
+    assertThat(Vote.dropVote(Address.fromHexString("1")).isDrop()).isEqualTo(true);
+  }
+}