diff --git a/bundles/org.eclipse.passage.lic.api/src/org/eclipse/passage/lic/internal/api/io/Hashes.java b/bundles/org.eclipse.passage.lic.api/src/org/eclipse/passage/lic/internal/api/io/Hashes.java
new file mode 100644
index 000000000..98280fb88
--- /dev/null
+++ b/bundles/org.eclipse.passage.lic.api/src/org/eclipse/passage/lic/internal/api/io/Hashes.java
@@ -0,0 +1,23 @@
+/*******************************************************************************
+ * Copyright (c) 2021 ArSysOp
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License 2.0 which is available at
+ * https://www.eclipse.org/legal/epl-2.0/.
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ *     ArSysOp - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.passage.lic.internal.api.io;
+
+import org.eclipse.passage.lic.internal.api.LicensingException;
+import org.eclipse.passage.lic.internal.api.registry.Service;
+import org.eclipse.passage.lic.internal.api.registry.StringServiceId;
+
+public interface Hashes extends Service<StringServiceId> {
+
+	byte[] get(byte[] source) throws LicensingException;
+
+}
diff --git a/bundles/org.eclipse.passage.lic.api/src/org/eclipse/passage/lic/internal/api/io/HashesRegistry.java b/bundles/org.eclipse.passage.lic.api/src/org/eclipse/passage/lic/internal/api/io/HashesRegistry.java
new file mode 100644
index 000000000..663a54aef
--- /dev/null
+++ b/bundles/org.eclipse.passage.lic.api/src/org/eclipse/passage/lic/internal/api/io/HashesRegistry.java
@@ -0,0 +1,22 @@
+/*******************************************************************************
+ * Copyright (c) 2020 ArSysOp
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License 2.0 which is available at
+ * https://www.eclipse.org/legal/epl-2.0/.
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ *     ArSysOp - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.passage.lic.internal.api.io;
+
+import java.util.function.Supplier;
+
+import org.eclipse.passage.lic.internal.api.registry.Registry;
+import org.eclipse.passage.lic.internal.api.registry.StringServiceId;
+
+public interface HashesRegistry extends Supplier<Registry<StringServiceId, Hashes>> {
+
+}
diff --git a/bundles/org.eclipse.passage.lic.base/src/org/eclipse/passage/lic/internal/base/io/KeyContent.java b/bundles/org.eclipse.passage.lic.base/src/org/eclipse/passage/lic/internal/base/io/KeyContent.java
new file mode 100644
index 000000000..6285906c8
--- /dev/null
+++ b/bundles/org.eclipse.passage.lic.base/src/org/eclipse/passage/lic/internal/base/io/KeyContent.java
@@ -0,0 +1,43 @@
+/*******************************************************************************
+ * Copyright (c) 2021 ArSysOp
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License 2.0 which is available at
+ * https://www.eclipse.org/legal/epl-2.0/.
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ *     ArSysOp - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.passage.lic.internal.base.io;
+
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+
+import org.eclipse.passage.lic.internal.api.LicensingException;
+import org.eclipse.passage.lic.internal.api.io.KeyKeeper;
+
+public final class KeyContent {
+
+	private final KeyKeeper keeper;
+
+	public KeyContent(KeyKeeper keeper) {
+		this.keeper = keeper;
+	}
+
+	public byte[] get() throws LicensingException {
+		try (InputStream in = keeper.productPublicKey(); ByteArrayOutputStream out = new ByteArrayOutputStream()) {
+			int acquired = -1;
+			byte[] buffer = new byte[1024];
+			while ((acquired = in.read(buffer)) != -1) {
+				out.write(buffer, 0, acquired);
+			}
+			return out.toByteArray();
+		} catch (IOException e) {
+			throw new LicensingException("Failed to read public key ", e); //$NON-NLS-1$
+		}
+	}
+
+}
diff --git a/bundles/org.eclipse.passage.lic.base/src/org/eclipse/passage/lic/internal/base/io/MD5Hashes.java b/bundles/org.eclipse.passage.lic.base/src/org/eclipse/passage/lic/internal/base/io/MD5Hashes.java
new file mode 100644
index 000000000..86ec74e41
--- /dev/null
+++ b/bundles/org.eclipse.passage.lic.base/src/org/eclipse/passage/lic/internal/base/io/MD5Hashes.java
@@ -0,0 +1,40 @@
+/*******************************************************************************
+ * Copyright (c) 2021 ArSysOp
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License 2.0 which is available at
+ * https://www.eclipse.org/legal/epl-2.0/.
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ *     ArSysOp - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.passage.lic.internal.base.io;
+
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
+
+import org.eclipse.passage.lic.internal.api.LicensingException;
+import org.eclipse.passage.lic.internal.api.io.Hashes;
+import org.eclipse.passage.lic.internal.api.registry.StringServiceId;
+
+public final class MD5Hashes implements Hashes {
+
+	private final String algorithm = "MD5"; //$NON-NLS-1$
+
+	@Override
+	public StringServiceId id() {
+		return new StringServiceId(algorithm);
+	}
+
+	@Override
+	public byte[] get(byte[] source) throws LicensingException {
+		try {
+			return MessageDigest.getInstance(algorithm).digest(source);
+		} catch (NoSuchAlgorithmException e) {
+			throw new LicensingException("Failed to build a hash ", e); //$NON-NLS-1$
+		}
+	}
+
+}
diff --git a/bundles/org.eclipse.passage.lic.base/src/org/eclipse/passage/lic/internal/base/registry/ReadOnlyRegistry.java b/bundles/org.eclipse.passage.lic.base/src/org/eclipse/passage/lic/internal/base/registry/ReadOnlyRegistry.java
index b9cbdf51f..96da5f694 100644
--- a/bundles/org.eclipse.passage.lic.base/src/org/eclipse/passage/lic/internal/base/registry/ReadOnlyRegistry.java
+++ b/bundles/org.eclipse.passage.lic.base/src/org/eclipse/passage/lic/internal/base/registry/ReadOnlyRegistry.java
@@ -28,4 +28,8 @@ public ReadOnlyRegistry(S service) {
 		super(Collections.singleton(service));
 	}
 
+	public ReadOnlyRegistry() {
+		super(Collections.emptyList());
+	}
+
 }
diff --git a/bundles/org.eclipse.passage.lic.net/src/org/eclipse/passage/lic/internal/net/io/SafePayload.java b/bundles/org.eclipse.passage.lic.net/src/org/eclipse/passage/lic/internal/net/io/SafePayload.java
new file mode 100644
index 000000000..3205a303b
--- /dev/null
+++ b/bundles/org.eclipse.passage.lic.net/src/org/eclipse/passage/lic/internal/net/io/SafePayload.java
@@ -0,0 +1,56 @@
+/*******************************************************************************
+ * Copyright (c) 2021 ArSysOp
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License 2.0 which is available at
+ * https://www.eclipse.org/legal/epl-2.0/.
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ *     ArSysOp - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.passage.lic.internal.net.io;
+
+import java.util.Base64;
+
+import org.eclipse.passage.lic.internal.api.LicensingException;
+import org.eclipse.passage.lic.internal.api.io.Hashes;
+import org.eclipse.passage.lic.internal.api.io.KeyKeeper;
+import org.eclipse.passage.lic.internal.base.io.KeyContent;
+
+public final class SafePayload {
+
+	private final Hashes hashes;
+	private final KeyKeeper keeper;
+
+	public SafePayload(KeyKeeper keeper, Hashes hashes) {
+		this.keeper = keeper;
+		this.hashes = hashes;
+	}
+
+	public byte[] encode(byte[] raw) throws LicensingException {
+		return transportable(coded(raw));
+	}
+
+	public byte[] decode(byte[] raw) throws LicensingException {
+		return coded(transported(raw));
+	}
+
+	private byte[] transportable(byte[] content) {
+		return Base64.getEncoder().encode(content);
+	}
+
+	private byte[] transported(byte[] content) {
+		return Base64.getDecoder().decode(content);
+	}
+
+	private byte[] coded(byte[] source) throws LicensingException {
+		return new SymmetricCode(key()).get(source);
+	}
+
+	private byte[] key() throws LicensingException {
+		return hashes.get(new KeyContent(keeper).get());
+	}
+
+}
diff --git a/bundles/org.eclipse.passage.lic.net/src/org/eclipse/passage/lic/internal/net/io/SymmetricCode.java b/bundles/org.eclipse.passage.lic.net/src/org/eclipse/passage/lic/internal/net/io/SymmetricCode.java
new file mode 100644
index 000000000..08dbde133
--- /dev/null
+++ b/bundles/org.eclipse.passage.lic.net/src/org/eclipse/passage/lic/internal/net/io/SymmetricCode.java
@@ -0,0 +1,41 @@
+/*******************************************************************************
+ * Copyright (c) 2021 ArSysOp
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License 2.0 which is available at
+ * https://www.eclipse.org/legal/epl-2.0/.
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ *     ArSysOp - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.passage.lic.internal.net.io;
+
+final class SymmetricCode {
+
+	private final byte[] key;
+
+	SymmetricCode(byte[] key) {
+		this.key = key;
+	}
+
+	byte[] get(byte[] source) {
+		int length = source.length;
+		byte[] cypher = enoughKey(length);
+		byte[] coded = new byte[length];
+		for (int i = 0; i < length; i++) {
+			coded[i] = (byte) (source[i] ^ cypher[i]);
+		}
+		return coded;
+	}
+
+	private byte[] enoughKey(int length) {
+		byte[] elongated = new byte[length];
+		for (int i = 0; i < length; i++) {
+			elongated[i] = key[i % key.length];
+		}
+		return elongated;
+	}
+
+}
diff --git a/tests/org.eclipse.passage.lic.net.tests/.settings/org.eclipse.core.resources.prefs b/tests/org.eclipse.passage.lic.net.tests/.settings/org.eclipse.core.resources.prefs
new file mode 100644
index 000000000..9e945b514
--- /dev/null
+++ b/tests/org.eclipse.passage.lic.net.tests/.settings/org.eclipse.core.resources.prefs
@@ -0,0 +1,2 @@
+eclipse.preferences.version=1
+encoding//src/org/eclipse/passage/lic/net/tests/io/SafePayloadTest.java=UTF-8
diff --git a/tests/org.eclipse.passage.lic.net.tests/resource/io/key.pub b/tests/org.eclipse.passage.lic.net.tests/resource/io/key.pub
new file mode 100644
index 000000000..629a69573
--- /dev/null
+++ b/tests/org.eclipse.passage.lic.net.tests/resource/io/key.pub
@@ -0,0 +1,19 @@
+-----BEGIN PGP PUBLIC KEY BLOCK-----
+Version: BCPG v1.65
+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+=eVWh
+-----END PGP PUBLIC KEY BLOCK-----
diff --git a/tests/org.eclipse.passage.lic.net.tests/src/org/eclipse/passage/lic/net/tests/io/SafePayloadTest.java b/tests/org.eclipse.passage.lic.net.tests/src/org/eclipse/passage/lic/net/tests/io/SafePayloadTest.java
new file mode 100644
index 000000000..c43683423
--- /dev/null
+++ b/tests/org.eclipse.passage.lic.net.tests/src/org/eclipse/passage/lic/net/tests/io/SafePayloadTest.java
@@ -0,0 +1,48 @@
+/*******************************************************************************
+ * Copyright (c) 2021 ArSysOp
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License 2.0 which is available at
+ * https://www.eclipse.org/legal/epl-2.0/.
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ *     ArSysOp - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.passage.lic.net.tests.io;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
+
+import java.nio.file.Paths;
+
+import org.eclipse.passage.lic.internal.api.LicensingException;
+import org.eclipse.passage.lic.internal.api.io.KeyKeeper;
+import org.eclipse.passage.lic.internal.base.io.FileKeyKeeper;
+import org.eclipse.passage.lic.internal.base.io.MD5Hashes;
+import org.eclipse.passage.lic.internal.net.io.SafePayload;
+import org.junit.Test;
+
+public final class SafePayloadTest {
+
+	@Test
+	public void symmetric() {
+		String original = "S0me sophisticäted Str!ng"; //$NON-NLS-1$
+		try {
+			byte[] encoded = new SafePayload(keerper(), new MD5Hashes()).encode(original.getBytes());
+			assertTrue(encoded.length > 0);
+			System.out.println(new String(encoded));
+			byte[] decoded = new SafePayload(keerper(), new MD5Hashes()).decode(encoded);
+			assertTrue(decoded.length > 0);
+			assertEquals(original, new String(decoded));
+		} catch (LicensingException e) {
+			fail("Not intended to fail on valid data"); //$NON-NLS-1$
+		}
+	}
+
+	private KeyKeeper keerper() throws LicensingException {
+		return new FileKeyKeeper(Paths.get("resource").resolve("io").resolve("key.pub")); //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
+	}
+}