diff --git a/src/main/java/com/sparrowwallet/drongo/ExtendedKey.java b/src/main/java/com/sparrowwallet/drongo/ExtendedKey.java
index 7c60780..232e41b 100644
--- a/src/main/java/com/sparrowwallet/drongo/ExtendedKey.java
+++ b/src/main/java/com/sparrowwallet/drongo/ExtendedKey.java
@@ -139,17 +139,25 @@ public class ExtendedKey {
     }
 
     public enum Header {
-        xprv("xprv", 0x0488ADE4, null),
+        xprv("xprv", 0x0488ADE4, ScriptType.P2PKH),
         xpub("xpub", 0x0488B21E, ScriptType.P2PKH),
+        yprv("yprv", 0x049D7878, ScriptType.P2SH_P2WPKH),
         ypub("ypub", 0x049D7CB2, ScriptType.P2SH_P2WPKH),
+        zprv("zprv", 0x04b2430c, ScriptType.P2WPKH),
         zpub("zpub", 0x04B24746, ScriptType.P2WPKH),
+        Yprv("Yprv", 0x0295b005, ScriptType.P2SH_P2WSH),
         Ypub("Ypub", 0x0295b43f, ScriptType.P2SH_P2WSH),
+        Zprv("Zprv", 0x02aa7a99, ScriptType.P2WSH),
         Zpub("Zpub", 0x02aa7ed3, ScriptType.P2WSH),
         tpub("tpub", 0x043587cf, ScriptType.P2PKH),
-        tprv("tprv", 0x04358394, null),
+        tprv("tprv", 0x04358394, ScriptType.P2PKH),
+        uprv("uprv", 0x044a4e28, ScriptType.P2SH_P2WPKH),
         upub("upub", 0x044a5262, ScriptType.P2SH_P2WPKH),
+        vprv("vprv", 0x045f18bc, ScriptType.P2WPKH),
         vpub("vpub", 0x045f1cf6, ScriptType.P2WPKH),
+        Uprv("Uprv", 0x024285b5, ScriptType.P2SH_P2WSH),
         Upub("Upub", 0x024289ef, ScriptType.P2SH_P2WSH),
+        Vprv("Vprv", 0x02575048, ScriptType.P2WSH),
         Vpub("Vpub", 0x02575483, ScriptType.P2WSH);
 
         private final String name;
@@ -184,16 +192,20 @@ public class ExtendedKey {
             throw new IllegalArgumentException("Unrecognised extended key header for extended key: " + xpub);
         }
 
-        public static Header fromScriptType(ScriptType scriptType) {
-            for(Header extendedKeyHeader : Header.values()) {
-                if(extendedKeyHeader.defaultScriptType != null && extendedKeyHeader.defaultScriptType.equals(scriptType)) {
-                    return extendedKeyHeader;
+        public static Header fromScriptType(ScriptType scriptType, boolean privateKey) {
+            for(Header header : Header.values()) {
+                if(header.defaultScriptType != null && header.defaultScriptType.equals(scriptType) && header.isPrivate() == privateKey) {
+                    return header;
                 }
             }
 
             return Header.xpub;
         }
 
+        private boolean isPrivate() {
+            return name.endsWith("prv");
+        }
+
         public static boolean isValidHeader(int header) {
             for(Header extendedKeyHeader : Header.values()) {
                 if(header == extendedKeyHeader.header) {
diff --git a/src/main/java/com/sparrowwallet/drongo/wallet/DeterministicSeed.java b/src/main/java/com/sparrowwallet/drongo/wallet/DeterministicSeed.java
index 342a1c7..1817a64 100644
--- a/src/main/java/com/sparrowwallet/drongo/wallet/DeterministicSeed.java
+++ b/src/main/java/com/sparrowwallet/drongo/wallet/DeterministicSeed.java
@@ -98,6 +98,15 @@ public class DeterministicSeed implements EncryptableItem {
         this.creationTimeSeconds = creationTimeSeconds;
     }
 
+    public boolean needPassphrase() {
+        if(isEncrypted()) {
+            throw new IllegalArgumentException("Cannot determine if passphrase is required in encrypted state");
+        }
+
+        byte[] mnemonicOnlySeed = Bip39MnemonicCode.toSeed(mnemonicCode, "");
+        return Arrays.equals(mnemonicOnlySeed, seed);
+    }
+
     private static byte[] getEntropy(SecureRandom random, int bits) {
         if(bits > MAX_SEED_ENTROPY_BITS) {
             throw new IllegalArgumentException("Requested entropy size too large");
@@ -188,6 +197,14 @@ public class DeterministicSeed implements EncryptableItem {
         return new DeterministicSeed(mnemonic, seed, passphrase, creationTimeSeconds);
     }
 
+    public DeterministicSeed setPassphrase(String passphrase) {
+        if(isEncrypted()) {
+            throw new UnsupportedOperationException("Cannot set passphrase on encrypted seed");
+        }
+
+        return new DeterministicSeed(mnemonicCode, seed, passphrase, creationTimeSeconds);
+    }
+
     @Override
     public boolean equals(Object o) {
         if (this == o) return true;
diff --git a/src/main/java/com/sparrowwallet/drongo/wallet/Keystore.java b/src/main/java/com/sparrowwallet/drongo/wallet/Keystore.java
index d9df900..4ee3531 100644
--- a/src/main/java/com/sparrowwallet/drongo/wallet/Keystore.java
+++ b/src/main/java/com/sparrowwallet/drongo/wallet/Keystore.java
@@ -90,10 +90,20 @@ public class Keystore {
         return HDKeyDerivation.createMasterPrivateKey(seed.getSeedBytes());
     }
 
-    public ExtendedKey getExtendedPrivateKey() {
+    public ExtendedKey getExtendedMasterPrivateKey() {
         return new ExtendedKey(getMasterPrivateKey(), new byte[4], ChildNumber.ZERO);
     }
 
+    public ExtendedKey getExtendedMasterPublicKey() {
+        return new ExtendedKey(getMasterPrivateKey().dropPrivateBytes(), new byte[4], ChildNumber.ZERO);
+    }
+
+    public ExtendedKey getExtendedPrivateKey() {
+        List<ChildNumber> derivation = getKeyDerivation().getDerivation();
+        DeterministicKey derivedKey = getExtendedMasterPrivateKey().getKey(derivation);
+        return new ExtendedKey(derivedKey, derivedKey.getParentFingerprint(), derivation.get(derivation.size() - 1));
+    }
+
     public boolean isValid() {
         if(label == null || source == null || walletModel == null || keyDerivation == null || extendedPublicKey == null) {
             return false;
@@ -107,7 +117,19 @@ public class Keystore {
             return false;
         }
 
-        //TODO: If source is SW_SEED, check seed field is filled
+        if(source == KeystoreSource.SW_SEED) {
+            if(seed == null) {
+                return false;
+            }
+
+            List<ChildNumber> derivation = getKeyDerivation().getDerivation();
+            DeterministicKey derivedKey = getExtendedMasterPrivateKey().getKey(derivation);
+            DeterministicKey derivedKeyPublicOnly = derivedKey.dropPrivateBytes().dropParent();
+            ExtendedKey xpub = new ExtendedKey(derivedKeyPublicOnly, derivedKey.getParentFingerprint(), derivation.get(derivation.size() - 1));
+            if(!xpub.equals(getExtendedPublicKey())) {
+                return false;
+            }
+        }
 
         return true;
     }
@@ -131,7 +153,7 @@ public class Keystore {
     public static Keystore fromSeed(DeterministicSeed seed, List<ChildNumber> derivation) {
         Keystore keystore = new Keystore();
         keystore.setSeed(seed);
-        ExtendedKey xprv = keystore.getExtendedPrivateKey();
+        ExtendedKey xprv = keystore.getExtendedMasterPrivateKey();
         String masterFingerprint = Utils.bytesToHex(xprv.getKey().getFingerprint());
         DeterministicKey derivedKey = xprv.getKey(derivation);
         DeterministicKey derivedKeyPublicOnly = derivedKey.dropPrivateBytes().dropParent();
@@ -146,6 +168,18 @@ public class Keystore {
         return keystore;
     }
 
+    public void setPassphrase(String passphrase) {
+        if(seed != null) {
+            seed = seed.setPassphrase(passphrase);
+        } else {
+            throw new UnsupportedOperationException("Cannot set passphrase on a keystore without a seed");
+        }
+    }
+
+    public boolean hasSeed() {
+        return seed != null;
+    }
+
     public boolean isEncrypted() {
         return seed != null && seed.isEncrypted();
     }
diff --git a/src/main/java/com/sparrowwallet/drongo/wallet/Wallet.java b/src/main/java/com/sparrowwallet/drongo/wallet/Wallet.java
index be34359..2f1300b 100644
--- a/src/main/java/com/sparrowwallet/drongo/wallet/Wallet.java
+++ b/src/main/java/com/sparrowwallet/drongo/wallet/Wallet.java
@@ -8,6 +8,7 @@ import com.sparrowwallet.drongo.protocol.ScriptType;
 import org.bouncycastle.crypto.params.KeyParameter;
 
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
 
@@ -102,11 +103,22 @@ public class Wallet {
             if(!keystore.isValid()) {
                 return false;
             }
+            if(derivationMatchesAnotherScriptType(keystore.getKeyDerivation().getDerivationPath())) {
+                return false;
+            }
         }
 
         return true;
     }
 
+    public boolean derivationMatchesAnotherScriptType(String derivationPath) {
+        if(scriptType != null && scriptType.getAccount(derivationPath) > -1) {
+            return false;
+        }
+
+        return Arrays.stream(ScriptType.values()).anyMatch(scriptType -> !scriptType.equals(this.scriptType) && scriptType.getAccount(derivationPath) > -1);
+    }
+
     public Wallet copy() {
         Wallet copy = new Wallet(name);
         copy.setPolicyType(policyType);
diff --git a/src/test/java/com/sparrowwallet/drongo/wallet/KeystoreTest.java b/src/test/java/com/sparrowwallet/drongo/wallet/KeystoreTest.java
index 8d2b661..6275f5b 100644
--- a/src/test/java/com/sparrowwallet/drongo/wallet/KeystoreTest.java
+++ b/src/test/java/com/sparrowwallet/drongo/wallet/KeystoreTest.java
@@ -14,7 +14,7 @@ public class KeystoreTest {
         DeterministicSeed seed = new DeterministicSeed(Utils.hexToBytes("727ecfcf0bce9d8ec0ef066f7aeb845c271bdd4ee06a37398cebd40dc810140bb620b6c10a8ad671afdceaf37aa55d92d6478f747e8b92430dd938ab5be961dd"), Collections.emptyList(), 0);
         keystore.setSeed(seed);
 
-        Assert.assertEquals("xprv9s21ZrQH143K3rN5vhm4bKDKsk1PmUK1mzxSMwkVSp2GbomwGmjLaGqrs8Nn9r14jCsfCNWfTR6pAtCsJutUH6QSHX65CePNW3YVyGxqvJa", keystore.getExtendedPrivateKey().toString());
+        Assert.assertEquals("xprv9s21ZrQH143K3rN5vhm4bKDKsk1PmUK1mzxSMwkVSp2GbomwGmjLaGqrs8Nn9r14jCsfCNWfTR6pAtCsJutUH6QSHX65CePNW3YVyGxqvJa", keystore.getExtendedMasterPrivateKey().toString());
     }
 
     @Test
@@ -23,7 +23,7 @@ public class KeystoreTest {
         DeterministicSeed seed = new DeterministicSeed(Utils.hexToBytes("4d8c47d0d6241169d0b17994219211c4a980f7146bb70dbc897416790e9de23a6265c708b88176e24f6eb7378a7c55cd4bdc067cafe574eaf3480f9a41c3c43c"), Collections.emptyList(), 0);
         keystore.setSeed(seed);
 
-        Assert.assertEquals("xprv9s21ZrQH143K4AkrxAyivDeTCWhZV6fdLfBRR8QerWe9hHiRqMjBMj9MFNef7oFufgcDcW54LhguPNm6MVLEMWPX5qxKhmNjCzi9Zy6yhkc", keystore.getExtendedPrivateKey().toString());
+        Assert.assertEquals("xprv9s21ZrQH143K4AkrxAyivDeTCWhZV6fdLfBRR8QerWe9hHiRqMjBMj9MFNef7oFufgcDcW54LhguPNm6MVLEMWPX5qxKhmNjCzi9Zy6yhkc", keystore.getExtendedMasterPrivateKey().toString());
     }
 
     @Test