diff --git a/pyeudiw/jwk/schema.py b/pyeudiw/jwk/schema.py
index a372eb6b..dede8c9c 100644
--- a/pyeudiw/jwk/schema.py
+++ b/pyeudiw/jwk/schema.py
@@ -1,6 +1,6 @@
 from typing import List, Literal, Optional
 
-from pydantic import BaseModel, validator
+from pydantic import BaseModel, field_validator
 
 
 class JwkSchema(BaseModel):
@@ -32,11 +32,11 @@ def check_value_for_ec(value, name, values):
         if "RSA" == values.get("kty") and value:
             raise ValueError(f"{name} must be present only for kty = EC")
 
-    @validator("n")
+    @field_validator("n")
     def validate_n(cls, n_value, values):
         cls.check_value_for_rsa(n_value, "n", values)
 
-    @validator("e")
+    @field_validator("e")
     def validate_e(cls, e_value, values):
         cls.check_value_for_rsa(e_value, "e", values)
 
@@ -46,15 +46,15 @@ class JwkSchemaEC(JwkSchema):
     y: Optional[str]  # Base64url-encoded
     crv: Optional[Literal["P-256", "P-384", "P-521"]]
 
-    @validator("x")
+    @field_validator("x")
     def validate_x(cls, x_value, values):
         cls.check_value_for_ec(x_value, "x", values)
 
-    @validator("y")
+    @field_validator("y")
     def validate_y(cls, y_value, values):
         cls.check_value_for_ec(y_value, "y", values)
 
-    @validator("crv")
+    @field_validator("crv")
     def validate_crv(cls, crv_value, values):
         cls.check_value_for_ec(crv_value, "crv", values)
 
diff --git a/pyeudiw/tools/jwt.py b/pyeudiw/jwt/__init__.py
similarity index 92%
rename from pyeudiw/tools/jwt.py
rename to pyeudiw/jwt/__init__.py
index 04f9b28f..5a55e2e0 100644
--- a/pyeudiw/tools/jwt.py
+++ b/pyeudiw/jwt/__init__.py
@@ -12,6 +12,7 @@
 from typing import Union
 
 from pyeudiw.jwk import JWK
+from pyeudiw.jwt.utils import unpad_jwt_header
 
 DEFAULT_HASH_FUNC = "SHA-256"
 
@@ -25,13 +26,6 @@
 DEFAULT_JWE_ENC = "A256CBC-HS512"
 
 
-def unpad_jwt_header(jwt: str) -> dict:
-    b = jwt.split(".")[0]
-    padded = f"{b}{'=' * divmod(len(b), 4)[1]}"
-    data = json.loads(base64.urlsafe_b64decode(padded))
-    return data
-
-
 class JWEHelper():
     def __init__(self, jwk: JWK):
         self.jwk = jwk
@@ -88,9 +82,11 @@ def decrypt(self, jwe: str) -> dict:
 
 
 class JWSHelper:
-    def __init__(self, jwk: JWK):
+    def __init__(self, jwk: Union[JWK, dict]):
         self.jwk = jwk
-        self.alg = DEFAUL_SIG_KTY_MAP[jwk.key.kty]
+        if isinstance(jwk, dict):
+            self.jwk = JWK(jwk)
+        self.alg = DEFAUL_SIG_KTY_MAP[self.jwk.key.kty]
 
     def sign(
         self,
diff --git a/pyeudiw/jwt/utils.py b/pyeudiw/jwt/utils.py
new file mode 100644
index 00000000..245c5cd2
--- /dev/null
+++ b/pyeudiw/jwt/utils.py
@@ -0,0 +1,31 @@
+import base64
+import json
+
+
+def unpad_jwt_element(jwt: str, position: int) -> dict:
+    b = jwt.split(".")[position]
+    padded = f"{b}{'=' * divmod(len(b), 4)[1]}"
+    data = json.loads(base64.urlsafe_b64decode(padded))
+    return data
+
+
+def unpad_jwt_header(jwt: str) -> dict:
+    return unpad_jwt_element(jwt, position=0)
+
+
+def unpad_jwt_payload(jwt: str) -> dict:
+    return unpad_jwt_element(jwt, position=1)
+
+
+def get_jwk_from_jwt(jwt: str, provider_jwks: dict) -> dict:
+    """
+        docs here
+    """
+    head = unpad_jwt_header(jwt)
+    kid = head["kid"]
+    if isinstance(provider_jwks, dict) and provider_jwks.get('keys'):
+        provider_jwks = provider_jwks['keys']
+    for jwk in provider_jwks:
+        if jwk["kid"] == kid:
+            return jwk
+    return {}
diff --git a/pyeudiw/oauth2/dpop.py b/pyeudiw/oauth2/dpop.py
index 065f6ef0..1ccec7b4 100644
--- a/pyeudiw/oauth2/dpop.py
+++ b/pyeudiw/oauth2/dpop.py
@@ -1,7 +1,11 @@
-from pydantic import BaseModel, HttpUrl
+import hashlib
+import uuid
 
+from pydantic import BaseModel, HttpUrl
 from pyeudiw.jwk.schema import JwkSchema
-
+from pyeudiw.jwt import JWSHelper
+from pyeudiw.jwt.utils import unpad_jwt_payload
+from pyeudiw.tools.utils import iat_now
 from typing import Literal
 
 
@@ -32,24 +36,46 @@ class DPoPTokenPayloadSchema(BaseModel):
 
 
 class DPoPIssuer:
-    def __init__(self, token: str, private_jwk: dict):
+    def __init__(self, htu :str, token: str, private_jwk: dict):
         self.token = token
         self.private_jwk = private_jwk
+        self.signer = JWSHelper(private_jwk)
+        self.htu = htu
 
     @property
     def proof(self):
-        pass
-
+        data = {
+            "jti": str(uuid.uuid4()),
+            "htm": "GET",
+            "htu": self.htu,
+            "iat": iat_now(),
+            "ath": hashlib.sha256(self.token.encode()).hexdigest()
+        }
+        jwt = self.signer.sign(data)
+        return jwt
+        # TODO assertion
 
 class DPoPVerifier:
+    dpop_header_prefix = 'DPoP '
+    
     def __init__(
-        self, token: str,
+        self,
         public_jwk: dict,
-        http_header_authz: str,
-        http_header_dpop: str,
+        http_header_authz :str,
+        http_header_dpop :str,
     ):
-        self.token = token
         self.public_jwk = public_jwk
-
-    def validate(self):
-        pass
+        self.dpop_token = (
+            http_header_authz.replace(self.dpop_header_prefix, '') 
+            if self.dpop_header_prefix in http_header_authz 
+            else http_header_authz
+        )
+        self.proof = http_header_dpop
+    
+    @property
+    def is_valid(self):
+        jws_verifier = JWSHelper(self.public_jwk)
+        dpop_valid = jws_verifier.verify(self.dpop_token)
+        payload = unpad_jwt_payload(self.proof)
+        proof_valid = hashlib.sha256(self.dpop_token.encode()).hexdigest() == payload['ath']
+        return dpop_valid and proof_valid 
diff --git a/pyeudiw/satosa/backend.py b/pyeudiw/satosa/backend.py
index 15a6804f..e03e1c33 100644
--- a/pyeudiw/satosa/backend.py
+++ b/pyeudiw/satosa/backend.py
@@ -12,7 +12,7 @@
 from pyeudiw.satosa.html_template import Jinja2TemplateHandler
 from pyeudiw.tools.qr_code import QRCode
 from pyeudiw.jwk import JWK
-from pyeudiw.tools.jwt import JWSHelper
+from pyeudiw.jwt import JWSHelper
 from pyeudiw.tools.mobile import is_smartphone
 
 logger = logging.getLogger("openid4vp_backend")
@@ -155,13 +155,7 @@ def redirect_endpoint(self, context, *args):
         jwk = self.metadata_jwk
 
         helper = JWSHelper(jwk)
-        data = {
-            "jti": str(uuid.uuid4()),
-            "htm": "GET",
-            "htu": f"{self.client_id}/request_uri",
-            "iat": int(datetime.now().timestamp()),
-            "ath": "fUHyO2r2Z3DZ53EsNrWBb0xWXoaNy59IiKCAqksmQEo"
-        }
+        data = {} #TODO
         jwt = helper.sign(data)
         response = {"request": jwt}
 
diff --git a/pyeudiw/tests/oauth2/test_dpop.py b/pyeudiw/tests/oauth2/test_dpop.py
index 0273085e..9d342782 100644
--- a/pyeudiw/tests/oauth2/test_dpop.py
+++ b/pyeudiw/tests/oauth2/test_dpop.py
@@ -1,10 +1,13 @@
 import pytest
 
+from pyeudiw.oauth2.dpop import DPoPIssuer, DPoPVerifier
 from pyeudiw.jwk import JWK
-from pyeudiw.tools.jwt import JWSHelper
+from pyeudiw.jwt import JWSHelper
+from pyeudiw.jwt.utils import unpad_jwt_payload, unpad_jwt_header
 from pyeudiw.tools.utils import iat_now
 
 
+
 WALLET_INSTANCE_ATTESTATION = {
     "iss": "https://wallet-provider.example.org",
     "sub": "vbeXJksM45xphtANnCiG6mCyuU4jfGNzopGuKvogg9c",
@@ -54,10 +57,35 @@ def private_jwk():
 def jwshelper(private_jwk):
     return JWSHelper(private_jwk)
 
+@pytest.fixture
+def wia_jws(jwshelper):
+    wia = jwshelper.sign(
+        WALLET_INSTANCE_ATTESTATION,
+        protected={'trust_chain': [], 'x5c': []}
+    )
+    return wia
 
-def test_create(jwshelper):
-    jwshelper.sign(WALLET_INSTANCE_ATTESTATION)
-
-
-def test_validate():
-    pass
+def test_create_validate_dpop_http_headers(wia_jws, private_jwk):
+    # create
+    header = unpad_jwt_header(wia_jws)
+    payload = unpad_jwt_payload(wia_jws)
+    # TODO assertions
+    
+    new_dpop = DPoPIssuer(
+        htu='https://example.org/redirect', 
+        token=wia_jws, 
+        private_jwk=private_jwk
+    )
+    proof = new_dpop.proof
+    
+    # TODO assertions
+    
+    # verify
+    dpop = DPoPVerifier(
+        public_jwk = private_jwk.public_key,
+        http_header_authz = f"DPoP {wia_jws}",
+        http_header_dpop = proof
+    )
+    
+    assert dpop.is_valid
+    # TODO assertions
diff --git a/pyeudiw/tests/tools/test_jwt.py b/pyeudiw/tests/tools/test_jwt.py
index 7d2fe990..78988a1b 100644
--- a/pyeudiw/tests/tools/test_jwt.py
+++ b/pyeudiw/tests/tools/test_jwt.py
@@ -1,7 +1,8 @@
 import pytest
 
 from pyeudiw.jwk import JWK
-from pyeudiw.tools.jwt import JWEHelper, JWSHelper, unpad_jwt_header, DEFAULT_JWE_ALG, DEFAULT_JWE_ENC
+from pyeudiw.jwt import JWEHelper, JWSHelper, DEFAULT_JWE_ALG, DEFAULT_JWE_ENC
+from pyeudiw.jwt.utils import unpad_jwt_header
 
 JWKs_EC = [
     (JWK(key_type="EC"), {"key": "value"}),
diff --git a/pyeudiw/tools/utils.py b/pyeudiw/tools/utils.py
index ea1d6e8b..5758ea08 100644
--- a/pyeudiw/tools/utils.py
+++ b/pyeudiw/tools/utils.py
@@ -2,8 +2,6 @@
 # from django.utils.timezone import make_aware
 from secrets import token_hex
 
-from . jwt import unpad_jwt_header
-
 
 import datetime
 import json
@@ -63,19 +61,5 @@ def get_jwks(httpc_params: dict, metadata: dict, federation_jwks: list = []) ->
     return jwks_list
 
 
-def get_jwk_from_jwt(jwt: str, provider_jwks: dict) -> dict:
-    """
-        docs here
-    """
-    head = unpad_jwt_header(jwt)
-    kid = head["kid"]
-    if isinstance(provider_jwks, dict) and provider_jwks.get('keys'):
-        provider_jwks = provider_jwks['keys']
-    for jwk in provider_jwks:
-        if jwk["kid"] == kid:
-            return jwk
-    return {}
-
-
 def random_token(n=254):
     return token_hex(n)