diff --git a/ykcs11/objects.c b/ykcs11/objects.c
index 99e6519..876bc57 100644
--- a/ykcs11/objects.c
+++ b/ykcs11/objects.c
@@ -1012,6 +1012,22 @@ CK_RV store_cert(piv_obj_id_t cert_id, CK_BYTE_PTR data, CK_ULONG len) {
   return CKR_OK;
 }
 
+CK_RV delete_cert(piv_obj_id_t cert_id) {
+  CK_RV rv;
+
+  // Clear the object containing the certificate
+  rv = do_delete_cert(&cert_objects[piv_objects[cert_id].sub_id].data);
+  if (rv != CKR_OK)
+    return rv;
+
+  // Clear the object containing the public key
+  rv = do_delete_pubk(&pubkey_objects[piv_objects[cert_id].sub_id].data);
+  if (rv != CKR_OK)
+    return rv;
+
+  return CKR_OK;
+}
+
 CK_RV check_create_cert(CK_ATTRIBUTE_PTR templ, CK_ULONG n,
                         CK_BYTE_PTR id, CK_BYTE_PTR *value, CK_ULONG_PTR cert_len) {
 
@@ -1263,3 +1279,13 @@ CK_RV check_create_rsa_key(CK_ATTRIBUTE_PTR templ, CK_ULONG n, CK_BYTE_PTR id,
 
   return CKR_OK;
 }
+
+CK_RV check_delete_cert(CK_OBJECT_HANDLE hObject, CK_BYTE_PTR id) {
+
+  if (hObject < PIV_CERT_OBJ_X509_PIV_AUTH || hObject >= PIV_CERT_OBJ_LAST)
+    return CKR_ACTION_PROHIBITED;
+
+  *id = hObject - PIV_CERT_OBJ_X509_PIV_AUTH;
+
+  return CKR_OK;
+}
diff --git a/ykcs11/objects.h b/ykcs11/objects.h
index 860f3a8..be9db19 100644
--- a/ykcs11/objects.h
+++ b/ykcs11/objects.h
@@ -11,6 +11,7 @@ CK_BBOOL is_private_object(ykcs11_session_t *s, CK_OBJECT_HANDLE obj);
 
 CK_RV    get_available_certificate_ids(ykcs11_session_t *s, piv_obj_id_t *cert_ids, CK_ULONG n_certs);
 CK_RV    store_cert(piv_obj_id_t cert_id, CK_BYTE_PTR data, CK_ULONG len);
+CK_RV     delete_cert(piv_obj_id_t cert_id);
 
 CK_RV check_create_cert(CK_ATTRIBUTE_PTR templ, CK_ULONG n, CK_BYTE_PTR id,
                         CK_BYTE_PTR *value, CK_ULONG_PTR cert_len);
@@ -19,6 +20,6 @@ CK_RV check_create_ec_key(CK_ATTRIBUTE_PTR templ, CK_ULONG n, CK_BYTE_PTR id,
 CK_RV check_create_rsa_key(CK_ATTRIBUTE_PTR templ, CK_ULONG n, CK_BYTE_PTR id,
                            CK_BYTE_PTR *p, CK_BYTE_PTR *q, CK_BYTE_PTR *dp,
                            CK_BYTE_PTR *dq, CK_BYTE_PTR *qinv, CK_ULONG_PTR value_len, CK_ULONG_PTR vendor_defined);
-
+CK_RV check_delete_cert(CK_OBJECT_HANDLE hObject, CK_BYTE_PTR id);
 
 #endif
diff --git a/ykcs11/openssl_utils.c b/ykcs11/openssl_utils.c
index 8b68c2d..cc2085a 100644
--- a/ykcs11/openssl_utils.c
+++ b/ykcs11/openssl_utils.c
@@ -256,12 +256,21 @@ CK_RV do_get_raw_cert(X509 *cert, CK_BYTE_PTR out, CK_ULONG_PTR out_len) {
   return CKR_OK;
 }
 
-CK_RV free_cert(X509 *cert) {
+CK_RV do_delete_cert(X509 **cert) {
+
+  X509_free(*cert);
+  cert = NULL;
+
+  return CKR_OK;
+
+}
+
+/*CK_RV free_cert(X509 *cert) {
 
   X509_free((X509 *) cert);
 
   return CKR_OK;
-}
+}*/
 
 
 CK_RV do_store_pubk(X509 *cert, EVP_PKEY **key) {
@@ -438,13 +447,22 @@ CK_RV do_get_curve_parameters(EVP_PKEY *key, CK_BYTE_PTR data, CK_ULONG_PTR len)
   return CKR_OK;
 }
 
-CK_RV free_key(EVP_PKEY *key) {
+CK_RV do_delete_pubk(EVP_PKEY **key) {
+
+  EVP_PKEY_free(*key);
+  key = NULL;
+
+  return CKR_OK;
+
+}
+
+/*CK_RV free_key(EVP_PKEY *key) {
 
   EVP_PKEY_free(key);
 
   return CKR_OK;
 
-}
+  }*/
 
 CK_RV do_pkcs_1_t1(CK_BYTE_PTR in, CK_ULONG in_len, CK_BYTE_PTR out, CK_ULONG_PTR out_len, CK_ULONG key_len) {
   unsigned char buffer[512];
diff --git a/ykcs11/openssl_utils.h b/ykcs11/openssl_utils.h
index 09f6482..35461a5 100644
--- a/ykcs11/openssl_utils.h
+++ b/ykcs11/openssl_utils.h
@@ -14,7 +14,8 @@ CK_RV do_create_empty_cert(CK_BYTE_PTR in, CK_ULONG in_len, CK_BBOOL is_rsa,
                            CK_BYTE_PTR out, CK_ULONG_PTR out_len);
 CK_RV do_check_cert(CK_BYTE_PTR in, CK_ULONG_PTR cert_len);
 CK_RV do_get_raw_cert(X509 *cert, CK_BYTE_PTR out, CK_ULONG_PTR out_len);
-CK_RV free_cert(X509 *cert);
+CK_RV do_delete_cert(X509 **cert);
+//CK_RV free_cert(X509 *cert);
 
 CK_RV       do_store_pubk(X509 *cert, EVP_PKEY **key);
 CK_KEY_TYPE do_get_key_type(EVP_PKEY *key);
@@ -23,7 +24,8 @@ CK_ULONG    do_get_public_exponent(EVP_PKEY *key);
 CK_RV       do_get_public_key(EVP_PKEY *key, CK_BYTE_PTR data, CK_ULONG_PTR len);
 CK_RV       do_encode_rsa_public_key(CK_BYTE_PTR data, CK_ULONG len, RSA **key);
 CK_RV       do_get_curve_parameters(EVP_PKEY *key, CK_BYTE_PTR data, CK_ULONG_PTR len);
-CK_RV       free_key(EVP_PKEY *key);
+CK_RV       do_delete_pubk(EVP_PKEY **key);
+//CK_RV       free_key(EVP_PKEY *key);
 
 CK_RV do_pkcs_1_t1(CK_BYTE_PTR in, CK_ULONG in_len, CK_BYTE_PTR out, CK_ULONG_PTR out_len, CK_ULONG key_len);
 CK_RV do_pkcs_1_digest_info(CK_BYTE_PTR in, CK_ULONG in_len, int nid, CK_BYTE_PTR out, CK_ULONG_PTR out_len);
diff --git a/ykcs11/pkcs11t.h b/ykcs11/pkcs11t.h
index bcdd9e0..d357092 100644
--- a/ykcs11/pkcs11t.h
+++ b/ykcs11/pkcs11t.h
@@ -755,6 +755,8 @@ typedef CK_ULONG          CK_RV;
 #define CKR_ATTRIBUTE_SENSITIVE               0x00000011UL
 #define CKR_ATTRIBUTE_TYPE_INVALID            0x00000012UL
 #define CKR_ATTRIBUTE_VALUE_INVALID           0x00000013UL
+#define CKR_COPY_PROHIBITED                   0x0000001AUL
+#define CKR_ACTION_PROHIBITED                 0x0000001BUL
 #define CKR_DATA_INVALID                      0x00000020UL
 #define CKR_DATA_LEN_RANGE                    0x00000021UL
 #define CKR_DEVICE_ERROR                      0x00000030UL
diff --git a/ykcs11/token_vendors.c b/ykcs11/token_vendors.c
index c185f7e..cb62e83 100644
--- a/ykcs11/token_vendors.c
+++ b/ykcs11/token_vendors.c
@@ -257,6 +257,14 @@ CK_RV COMMON_token_import_private_key(ykpiv_state *state, CK_BYTE key_id, CK_BYT
 
 }
 
+CK_RV COMMON_token_delete_cert(ykpiv_state *state, CK_ULONG cert_id) {
+
+  if (ykpiv_save_object(state, cert_id, NULL, 0) != YKPIV_OK)
+    return CKR_DEVICE_ERROR;
+
+  return CKR_OK;
+}
+
 token_vendor_t get_token_vendor(vendor_id_t vid) {
   token_vendor_t v;
 
@@ -278,6 +286,7 @@ token_vendor_t get_token_vendor(vendor_id_t vid) {
     v.token_generate_key        = COMMON_token_generate_key;
     v.token_import_cert         = COMMON_token_import_cert;
     v.token_import_private_key  = COMMON_token_import_private_key;
+    v.token_delete_cert         = COMMON_token_delete_cert;
     break;
 
   case UNKNOWN:
@@ -298,6 +307,7 @@ token_vendor_t get_token_vendor(vendor_id_t vid) {
     v.token_generate_key        = NULL;
     v.token_import_cert         = NULL;
     v.token_import_private_key  = NULL;
+    v.token_delete_cert         = NULL;
   }
 
   return v;
diff --git a/ykcs11/token_vendors.h b/ykcs11/token_vendors.h
index 9513063..3b57209 100644
--- a/ykcs11/token_vendors.h
+++ b/ykcs11/token_vendors.h
@@ -25,6 +25,7 @@ typedef CK_RV (*t_generate_key_f)(ykpiv_state *, CK_BBOOL, CK_BYTE, CK_ULONG, CK
 typedef CK_RV (*t_import_cert_f)(ykpiv_state *, CK_ULONG, CK_BYTE_PTR);
 typedef CK_RV (*t_import_private_key_f)(ykpiv_state *, CK_BYTE, CK_BYTE_PTR, CK_BYTE_PTR, CK_BYTE_PTR,
                                         CK_BYTE_PTR, CK_BYTE_PTR, CK_BYTE_PTR, CK_ULONG, CK_ULONG);
+typedef CK_RV (*t_delete_cert_f)(ykpiv_state *, CK_ULONG);
 
 // TODO: replace all the common calls with functions defined in .c that use libykpiv
 
@@ -45,6 +46,7 @@ typedef struct {
   t_generate_key_f        token_generate_key;
   t_import_cert_f         token_import_cert;
   t_import_private_key_f  token_import_private_key;
+  t_delete_cert_f         token_delete_cert;
 } token_vendor_t;
 
 token_vendor_t get_token_vendor(vendor_id_t vid);
diff --git a/ykcs11/ykcs11.c b/ykcs11/ykcs11.c
index 32715c0..4d76606 100644
--- a/ykcs11/ykcs11.c
+++ b/ykcs11/ykcs11.c
@@ -1044,7 +1044,93 @@ CK_DEFINE_FUNCTION(CK_RV, C_DestroyObject)(
 )
 {
   DIN;
-  DBG(("TODO!!!"));
+
+  CK_RV          rv;
+  token_vendor_t token;
+  CK_ULONG       i;
+  CK_ULONG       j;
+  CK_BYTE        id;
+  CK_ULONG       cert_id;
+  CK_ULONG       pvtk_id;
+  CK_ULONG       pubk_id;
+  piv_obj_id_t   *obj_ptr;
+
+  DBG(("Deleting object %lu", hObject));
+
+  if (piv_state == NULL) {
+    DBG(("libykpiv is not initialized or already finalized"));
+    return CKR_CRYPTOKI_NOT_INITIALIZED;
+  }
+
+  if (session.handle != YKCS11_SESSION_ID) {
+    DBG(("Session is not open"));
+    return CKR_SESSION_CLOSED;
+  }
+
+  if (hSession != session.handle) {
+    DBG(("Unknown session %lu", hSession));
+    return CKR_SESSION_HANDLE_INVALID;
+  }
+
+  // Only certificates can be deleted
+  // SO must be logged in
+  if (session.info.state != CKS_RW_SO_FUNCTIONS) {
+    DBG(("Unable to delete objects, SO must be logged in"));
+    return CKR_ACTION_PROHIBITED;
+  }
+
+  rv = check_delete_cert(hObject, &id);
+  if (rv != CKR_OK) {
+    DBG(("Object %lu can not be deleted", hObject));
+    return rv;
+  }
+
+  token = get_token_vendor(session.slot->token->vid);
+
+  rv = token.token_delete_cert(piv_state, piv_2_ykpiv(hObject));
+  if (rv != CKR_OK) {
+    DBG(("Unable to delete object %lu", hObject));
+    return rv;
+  }
+
+  // Remove the object from the session
+  // Do it in a slightly inefficient way but preserve ordering
+
+  cert_id = PIV_CERT_OBJ_X509_PIV_AUTH + id; // TODO: make function for these
+  pvtk_id = PIV_PVTK_OBJ_PIV_AUTH + id;
+  pubk_id = PIV_PUBK_OBJ_PIV_AUTH + id;
+
+  obj_ptr = malloc((session.slot->token->n_objects - 3) * sizeof(piv_obj_id_t));
+  if (obj_ptr == NULL) {
+    DBG(("Unable to allocate memory"));
+    return CKR_HOST_MEMORY;
+  }
+
+  i = 0;
+  j = 0;
+  while (i < session.slot->token->n_objects) {
+    if (session.slot->token->objects[i] == cert_id ||
+        session.slot->token->objects[i] == pvtk_id ||
+        session.slot->token->objects[i] == pubk_id) {
+      i++;
+      continue;
+    }
+
+    obj_ptr[j++] = session.slot->token->objects[i++];
+  }
+
+  rv = delete_cert(cert_id);
+  if (rv != CKR_OK) {
+    DBG(("Unable to delete certificate data"));
+    return CKR_FUNCTION_FAILED;
+  }
+
+  free(session.slot->token->objects);
+
+  session.slot->token->n_objects -= 3;
+  session.slot->token->n_certs--;
+  session.slot->token->objects = obj_ptr;
+
   DOUT;
   return CKR_OK;
 }