diff --git a/scripts/imgtool/image.py b/scripts/imgtool/image.py
index bd681c7..14265d5 100644
--- a/scripts/imgtool/image.py
+++ b/scripts/imgtool/image.py
@@ -26,8 +26,9 @@
 import hashlib
 import struct
 import os.path
-from .keys import rsa, ecdsa
+from .keys import rsa, ecdsa, x25519
 from cryptography.hazmat.primitives.asymmetric import ec, padding
+from cryptography.hazmat.primitives.asymmetric.x25519 import X25519PrivateKey
 from cryptography.hazmat.primitives.ciphers import Cipher, algorithms, modes
 from cryptography.hazmat.primitives.kdf.hkdf import HKDF
 from cryptography.hazmat.primitives.serialization import Encoding, PublicFormat
@@ -64,6 +65,7 @@
         'ENCRSA2048': 0x30,
         'ENCKW128': 0x31,
         'ENCEC256': 0x32,
+        'ENCX25519': 0x33,
         'DEPENDENCY': 0x40,
         'SEC_CNT': 0x50,
         'BOOT_RECORD': 0x60,
@@ -241,9 +243,13 @@
                           len(self.payload), tsize, self.slot_size)
                 raise click.UsageError(msg)
 
-    def ecies_p256_hkdf(self, enckey, plainkey):
-        newpk = ec.generate_private_key(ec.SECP256R1(), default_backend())
-        shared = newpk.exchange(ec.ECDH(), enckey._get_public())
+    def ecies_hkdf(self, enckey, plainkey):
+        if isinstance(enckey, ecdsa.ECDSA256P1Public):
+            newpk = ec.generate_private_key(ec.SECP256R1(), default_backend())
+            shared = newpk.exchange(ec.ECDH(), enckey._get_public())
+        else:
+            newpk = X25519PrivateKey.generate()
+            shared = newpk.exchange(enckey._get_public())
         derived_key = HKDF(
             algorithm=hashes.SHA256(), length=48, salt=None,
             info=b'MCUBoot_ECIES_v1', backend=default_backend()).derive(shared)
@@ -255,9 +261,14 @@
                         backend=default_backend())
         mac.update(cipherkey)
         ciphermac = mac.finalize()
-        pubk = newpk.public_key().public_bytes(
-            encoding=Encoding.X962,
-            format=PublicFormat.UncompressedPoint)
+        if isinstance(enckey, ecdsa.ECDSA256P1Public):
+            pubk = newpk.public_key().public_bytes(
+                encoding=Encoding.X962,
+                format=PublicFormat.UncompressedPoint)
+        else:
+            pubk = newpk.public_key().public_bytes(
+                encoding=Encoding.Raw,
+                format=PublicFormat.Raw)
         return cipherkey, ciphermac, pubk
 
     def create(self, key, public_key_format, enckey, dependencies=None,
@@ -392,11 +403,15 @@
                         label=None))
                 self.enctlv_len = len(cipherkey)
                 tlv.add('ENCRSA2048', cipherkey)
-            elif isinstance(enckey, ecdsa.ECDSA256P1Public):
-                cipherkey, mac, pubk = self.ecies_p256_hkdf(enckey, plainkey)
+            elif isinstance(enckey, (ecdsa.ECDSA256P1Public,
+                                     x25519.X25519Public)):
+                cipherkey, mac, pubk = self.ecies_hkdf(enckey, plainkey)
                 enctlv = pubk + mac + cipherkey
                 self.enctlv_len = len(enctlv)
-                tlv.add('ENCEC256', enctlv)
+                if isinstance(enckey, ecdsa.ECDSA256P1Public):
+                    tlv.add('ENCEC256', enctlv)
+                else:
+                    tlv.add('ENCX25519', enctlv)
 
             nonce = bytes([0] * 16)
             cipher = Cipher(algorithms.AES(plainkey), modes.CTR(nonce),
diff --git a/scripts/imgtool/keys/__init__.py b/scripts/imgtool/keys/__init__.py
index 1145735..af6caff 100644
--- a/scripts/imgtool/keys/__init__.py
+++ b/scripts/imgtool/keys/__init__.py
@@ -18,19 +18,27 @@
 
 from cryptography.hazmat.backends import default_backend
 from cryptography.hazmat.primitives import serialization
-from cryptography.hazmat.primitives.asymmetric.rsa import RSAPrivateKey, RSAPublicKey
-from cryptography.hazmat.primitives.asymmetric.ec import EllipticCurvePrivateKey, EllipticCurvePublicKey
-from cryptography.hazmat.primitives.asymmetric.ed25519 import Ed25519PrivateKey, Ed25519PublicKey
+from cryptography.hazmat.primitives.asymmetric.rsa import (
+    RSAPrivateKey, RSAPublicKey)
+from cryptography.hazmat.primitives.asymmetric.ec import (
+    EllipticCurvePrivateKey, EllipticCurvePublicKey)
+from cryptography.hazmat.primitives.asymmetric.ed25519 import (
+    Ed25519PrivateKey, Ed25519PublicKey)
+from cryptography.hazmat.primitives.asymmetric.x25519 import (
+    X25519PrivateKey, X25519PublicKey)
 
 from .rsa import RSA, RSAPublic, RSAUsageError, RSA_KEY_SIZES
 from .ecdsa import ECDSA256P1, ECDSA256P1Public, ECDSAUsageError
 from .ed25519 import Ed25519, Ed25519Public, Ed25519UsageError
+from .x25519 import X25519, X25519Public, X25519UsageError
+
 
 class PasswordRequired(Exception):
     """Raised to indicate that the key is password protected, but a
     password was not specified."""
     pass
 
+
 def load(path, passwd=None):
     """Try loading a key from the given path.  Returns None if the password wasn't specified."""
     with open(path, 'rb') as f:
@@ -78,5 +86,9 @@
         return Ed25519(pk)
     elif isinstance(pk, Ed25519PublicKey):
         return Ed25519Public(pk)
+    elif isinstance(pk, X25519PrivateKey):
+        return X25519(pk)
+    elif isinstance(pk, X25519PublicKey):
+        return X25519Public(pk)
     else:
         raise Exception("Unknown key type: " + str(type(pk)))
diff --git a/scripts/imgtool/keys/x25519.py b/scripts/imgtool/keys/x25519.py
new file mode 100644
index 0000000..6c6f60f
--- /dev/null
+++ b/scripts/imgtool/keys/x25519.py
@@ -0,0 +1,105 @@
+"""
+X25519 key management
+"""
+
+from cryptography.hazmat.backends import default_backend
+from cryptography.hazmat.primitives import serialization
+from cryptography.hazmat.primitives.asymmetric import x25519
+
+from .general import KeyClass
+
+
+class X25519UsageError(Exception):
+    pass
+
+
+class X25519Public(KeyClass):
+    def __init__(self, key):
+        self.key = key
+
+    def shortname(self):
+        return "x25519"
+
+    def _unsupported(self, name):
+        raise X25519UsageError("Operation {} requires private key".format(name))
+
+    def _get_public(self):
+        return self.key
+
+    def get_public_bytes(self):
+        # The key is embedded into MBUboot in "SubjectPublicKeyInfo" format
+        return self._get_public().public_bytes(
+                encoding=serialization.Encoding.DER,
+                format=serialization.PublicFormat.SubjectPublicKeyInfo)
+
+    def get_private_bytes(self, minimal):
+        self._unsupported('get_private_bytes')
+
+    def export_private(self, path, passwd=None):
+        self._unsupported('export_private')
+
+    def export_public(self, path):
+        """Write the public key to the given file."""
+        pem = self._get_public().public_bytes(
+                encoding=serialization.Encoding.PEM,
+                format=serialization.PublicFormat.SubjectPublicKeyInfo)
+        with open(path, 'wb') as f:
+            f.write(pem)
+
+    def sig_type(self):
+        return "X25519"
+
+    def sig_tlv(self):
+        return "X25519"
+
+    def sig_len(self):
+        return 32
+
+
+class X25519(X25519Public):
+    """
+    Wrapper around an X25519 private key.
+    """
+
+    def __init__(self, key):
+        """key should be an instance of EllipticCurvePrivateKey"""
+        self.key = key
+
+    @staticmethod
+    def generate():
+        pk = x25519.X25519PrivateKey.generate()
+        return X25519(pk)
+
+    def _get_public(self):
+        return self.key.public_key()
+
+    def get_private_bytes(self, minimal):
+        raise X25519UsageError("Operation not supported with {} keys".format(
+            self.shortname()))
+
+    def export_private(self, path, passwd=None):
+        """
+        Write the private key to the given file, protecting it with the
+        optional password.
+        """
+        if passwd is None:
+            enc = serialization.NoEncryption()
+        else:
+            enc = serialization.BestAvailableEncryption(passwd)
+        pem = self.key.private_bytes(
+                encoding=serialization.Encoding.PEM,
+                format=serialization.PrivateFormat.PKCS8,
+                encryption_algorithm=enc)
+        with open(path, 'wb') as f:
+            f.write(pem)
+
+    def sign_digest(self, digest):
+        """Return the actual signature"""
+        return self.key.sign(data=digest)
+
+    def verify_digest(self, signature, digest):
+        """Verify that signature is valid for given digest"""
+        k = self.key
+        if isinstance(self.key, x25519.X25519PrivateKey):
+            k = self.key.public_key()
+        return k.verify(signature=signature, data=digest)