diff --git a/src/auditor/report-lib.c b/src/auditor/report-lib.c
index cc1b48b6a..e6468f692 100644
--- a/src/auditor/report-lib.c
+++ b/src/auditor/report-lib.c
@@ -151,7 +151,7 @@ add_denomination (
                        &issue->value);
     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                 "Tracking denomination `%s' (%s)\n",
-                GNUNET_h2s (&issue->denom_hash),
+                GNUNET_h2s (&issue->denom_hash.hash),
                 TALER_amount2s (&value));
     TALER_amount_ntoh (&value,
                        &issue->fee_withdraw);
diff --git a/src/auditordb/test_auditordb.c b/src/auditordb/test_auditordb.c
index 7e5a97035..38f0c24f4 100644
--- a/src/auditordb/test_auditordb.c
+++ b/src/auditordb/test_auditordb.c
@@ -142,12 +142,11 @@ run (void *cls)
   RND_BLK (&master_pub);
   RND_BLK (&reserve_pub);
   RND_BLK (&rnd_hash);
-  denom_priv.cipher = TALER_DENOMINATION_RSA;
-  denom_priv.details.rsa_private_key = GNUNET_CRYPTO_rsa_private_key_create (
-    1024);
-  TALER_denom_priv_to_pub (&denom_priv,
-                           0, /* age mask */
-                           &denom_pub);
+  GNUNET_assert (GNUNET_OK ==
+                 TALER_denom_priv_create (&denom_priv,
+                                          &denom_pub,
+                                          TALER_DENOMINATION_RSA,
+                                          1024));
   TALER_denom_pub_hash (&denom_pub,
                         &denom_pub_hash);
   TALER_denom_priv_free (&denom_priv);
diff --git a/src/benchmark/taler-aggregator-benchmark.c b/src/benchmark/taler-aggregator-benchmark.c
index 34c45b5cd..35d6af6fe 100644
--- a/src/benchmark/taler-aggregator-benchmark.c
+++ b/src/benchmark/taler-aggregator-benchmark.c
@@ -479,17 +479,16 @@ run (void *cls,
         GNUNET_TIME_absolute_add (end,
                                   GNUNET_TIME_UNIT_YEARS));
   {
-    struct GNUNET_CRYPTO_RsaPrivateKey *pk;
-    struct GNUNET_CRYPTO_RsaPublicKey *pub;
+    struct TALER_DenominationPrivateKey pk;
     struct GNUNET_HashCode hc;
-    struct TALER_DenominationPublicKey denom_pub = {
-      .cipher = TALER_DENOMINATION_RSA
-    };
+    struct TALER_DenominationPublicKey denom_pub;
 
     RANDOMIZE (&hc);
-    pk = GNUNET_CRYPTO_rsa_private_key_create (1024);
-    pub = GNUNET_CRYPTO_rsa_private_key_get_public (pk);
-    denom_pub.details.rsa_public_key = pub;
+    GNUNET_assert (GNUNET_OK ==
+                   TALER_denom_priv_create (&pk,
+                                            &denom_pub,
+                                            TALER_DENOMINATION_RSA,
+                                            1024));
     TALER_denom_pub_hash (&denom_pub,
                           &h_denom_pub);
     make_amountN (2, 0, &issue.properties.value);
@@ -510,10 +509,10 @@ run (void *cls,
     }
     denom_sig.cipher = TALER_DENOMINATION_RSA;
     denom_sig.details.rsa_signature
-      = GNUNET_CRYPTO_rsa_sign_fdh (pk,
+      = GNUNET_CRYPTO_rsa_sign_fdh (pk.details.rsa_private_key,
                                     &hc);
     TALER_denom_pub_free (&denom_pub);
-    GNUNET_CRYPTO_rsa_private_key_free (pk);
+    TALER_denom_priv_free (&pk);
   }
 
   {
diff --git a/src/exchangedb/test_exchangedb.c b/src/exchangedb/test_exchangedb.c
index 44ae56803..76a83a1b4 100644
--- a/src/exchangedb/test_exchangedb.c
+++ b/src/exchangedb/test_exchangedb.c
@@ -225,14 +225,11 @@ create_denom_key_pair (unsigned int size,
   struct TALER_EXCHANGEDB_DenominationKeyInformationP issue2;
 
   dkp = GNUNET_new (struct DenomKeyPair);
-  dkp->priv.cipher = TALER_DENOMINATION_RSA;
-  dkp->priv.details.rsa_private_key = GNUNET_CRYPTO_rsa_private_key_create (
-    size);
-  GNUNET_assert (NULL != dkp->priv.details.rsa_private_key);
-  TALER_denom_priv_to_pub (&dkp->priv,
-                           0, /* age mask */
-                           &dkp->pub);
-
+  GNUNET_assert (GNUNET_OK ==
+                 TALER_denom_priv_create (&dkp->priv,
+                                          &dkp->pub,
+                                          TALER_DENOMINATION_RSA,
+                                          size));
   /* Using memset() as fields like master key and signature
      are not properly initialized for this test. */
   memset (&dki,
diff --git a/src/include/taler_crypto_lib.h b/src/include/taler_crypto_lib.h
index 8871369e2..b726972ce 100644
--- a/src/include/taler_crypto_lib.h
+++ b/src/include/taler_crypto_lib.h
@@ -677,6 +677,26 @@ void
 TALER_denom_pub_free (struct TALER_DenominationPublicKey *denom_pub);
 
 
+/**
+ * Initialize denomination public-private key pair.
+ *
+ * For #TALER_DENOMINATION_RSA, an additional "unsigned int"
+ * argument with the number of bits for 'n' (e.g. 2048) must
+ * be passed.
+ *
+ * @param[out] denom_priv where to write the private key
+ * @param[out] deonm_pub where to write the public key
+ * @param cipher which type of cipher to use
+ * @param ... cipher-specific parameters
+ * @return #GNUNET_OK on success, #GNUNET_NO if parameters were invalid
+ */
+enum GNUNET_GenericReturnValue
+TALER_denom_priv_create (struct TALER_DenominationPrivateKey *denom_priv,
+                         struct TALER_DenominationPublicKey *denom_pub,
+                         enum TALER_DenominationCipher cipher,
+                         ...);
+
+
 /**
  * Free internals of @a denom_priv, but not @a denom_priv itself.
  *
@@ -695,6 +715,22 @@ void
 TALER_denom_sig_free (struct TALER_DenominationSignature *denom_sig);
 
 
+/**
+ * Create blinded signature.
+ *
+ * @param[out] denom_sig where to write the signature
+ * @param denom_priv private key to use for signing
+ * @param blinded_msg message to sign
+ * @param blinded_msg_size number of bytes in @a blinded_msg
+ * @return #GNUNET_OK on success
+ */
+enum GNUNET_GenericReturnValue
+TALER_denom_sign_blinded (struct TALER_BlindedDenominationSignature *denom_sig,
+                          const struct TALER_DenominationPrivateKey *denom_priv,
+                          void *blinded_msg,
+                          size_t blinded_msg_size);
+
+
 /**
  * Free internals of @a denom_sig, but not @a denom_sig itself.
  *
diff --git a/src/testing/testing_api_cmd_insert_deposit.c b/src/testing/testing_api_cmd_insert_deposit.c
index cc427ff5e..88ced9c2c 100644
--- a/src/testing/testing_api_cmd_insert_deposit.c
+++ b/src/testing/testing_api_cmd_insert_deposit.c
@@ -136,17 +136,17 @@ insert_deposit_run (void *cls,
   struct TALER_EXCHANGEDB_Deposit deposit;
   struct TALER_MerchantPrivateKeyP merchant_priv;
   struct TALER_EXCHANGEDB_DenominationKeyInformationP issue;
-  struct TALER_DenominationPublicKey dpk = {
-    .cipher = TALER_DENOMINATION_RSA
-  };
-  struct GNUNET_CRYPTO_RsaPrivateKey *denom_priv;
+  struct TALER_DenominationPublicKey dpk;
+  struct TALER_DenominationPrivateKey denom_priv;
   struct GNUNET_HashCode hc;
 
   // prepare and store issue first.
   fake_issue (&issue);
-  denom_priv = GNUNET_CRYPTO_rsa_private_key_create (1024);
-  dpk.details.rsa_public_key = GNUNET_CRYPTO_rsa_private_key_get_public (
-    denom_priv);
+  GNUNET_assert (GNUNET_OK ==
+                 TALER_denom_priv_create (&denom_priv,
+                                          &dpk,
+                                          TALER_DENOMINATION_RSA,
+                                          1024));
   TALER_denom_pub_hash (&dpk,
                         &issue.properties.denom_hash);
 
@@ -161,6 +161,8 @@ insert_deposit_run (void *cls,
         ids->dbc->plugin->commit (ids->dbc->plugin->cls)) )
   {
     TALER_TESTING_interpreter_fail (is);
+    TALER_denom_pub_free (&dpk);
+    TALER_denom_priv_free (&denom_priv);
     return;
   }
 
@@ -189,6 +191,8 @@ insert_deposit_run (void *cls,
                                 &deposit.deposit_fee)) )
   {
     TALER_TESTING_interpreter_fail (is);
+    TALER_denom_pub_free (&dpk);
+    TALER_denom_priv_free (&denom_priv);
     return;
   }
 
@@ -201,7 +205,7 @@ insert_deposit_run (void *cls,
                                     &hc);
   deposit.coin.denom_sig.cipher = TALER_DENOMINATION_RSA;
   deposit.coin.denom_sig.details.rsa_signature
-    = GNUNET_CRYPTO_rsa_sign_fdh (denom_priv,
+    = GNUNET_CRYPTO_rsa_sign_fdh (denom_priv.details.rsa_private_key,
                                   &hc);
   GNUNET_asprintf (&deposit.receiver_wire_account,
                    "payto://x-taler-bank/localhost/%s",
@@ -231,13 +235,15 @@ insert_deposit_run (void *cls,
     GNUNET_break (0);
     ids->dbc->plugin->rollback (ids->dbc->plugin->cls);
     GNUNET_free (deposit.receiver_wire_account);
+    TALER_denom_pub_free (&dpk);
+    TALER_denom_priv_free (&denom_priv);
     TALER_TESTING_interpreter_fail (is);
     return;
   }
 
   TALER_denom_sig_free (&deposit.coin.denom_sig);
   TALER_denom_pub_free (&dpk);
-  GNUNET_CRYPTO_rsa_private_key_free (denom_priv);
+  TALER_denom_priv_free (&denom_priv);
   GNUNET_free (deposit.receiver_wire_account);
   TALER_TESTING_interpreter_next (is);
 }
diff --git a/src/util/denom.c b/src/util/denom.c
index 15ba1c1ae..f251d9052 100644
--- a/src/util/denom.c
+++ b/src/util/denom.c
@@ -22,6 +22,93 @@
 #include "taler_util.h"
 
 
+enum GNUNET_GenericReturnValue
+TALER_denom_priv_create (struct TALER_DenominationPrivateKey *denom_priv,
+                         struct TALER_DenominationPublicKey *denom_pub,
+                         enum TALER_DenominationCipher cipher,
+                         ...)
+{
+  memset (denom_priv,
+          0,
+          sizeof (*denom_priv));
+  memset (denom_pub,
+          0,
+          sizeof (*denom_pub));
+  switch (cipher)
+  {
+  case TALER_DENOMINATION_INVALID:
+    GNUNET_break (0);
+    return GNUNET_SYSERR;
+  case TALER_DENOMINATION_RSA:
+    {
+      va_list ap;
+      unsigned int bits;
+
+      va_start (ap, cipher);
+      bits = va_arg (ap, unsigned int);
+      va_end (ap);
+      if (bits < 512)
+      {
+        GNUNET_break (0);
+        return GNUNET_SYSERR;
+      }
+      denom_priv->details.rsa_private_key
+        = GNUNET_CRYPTO_rsa_private_key_create (bits);
+    }
+    if (NULL == denom_priv->details.rsa_private_key)
+    {
+      GNUNET_break (0);
+      return GNUNET_SYSERR;
+    }
+    denom_pub->details.rsa_public_key
+      = GNUNET_CRYPTO_rsa_private_key_get_public (
+          denom_priv->details.rsa_private_key);
+    denom_priv->cipher = cipher;
+    denom_pub->cipher = cipher;
+    return GNUNET_OK;
+  // TODO: add case for Clause-Schnorr
+  default:
+    GNUNET_break (0);
+  }
+  return GNUNET_SYSERR;
+}
+
+
+enum GNUNET_GenericReturnValue
+TALER_denom_sign_blinded (struct TALER_BlindedDenominationSignature *denom_sig,
+                          const struct TALER_DenominationPrivateKey *denom_priv,
+                          void *blinded_msg,
+                          size_t blinded_msg_size)
+{
+  memset (denom_sig,
+          0,
+          sizeof (*denom_sig));
+  switch (denom_priv->cipher)
+  {
+  case TALER_DENOMINATION_INVALID:
+    GNUNET_break (0);
+    return GNUNET_SYSERR;
+  case TALER_DENOMINATION_RSA:
+    denom_sig->details.blinded_rsa_signature
+      = GNUNET_CRYPTO_rsa_sign_blinded (
+          denom_priv->details.rsa_private_key,
+          blinded_msg,
+          blinded_msg_size);
+    if (NULL == denom_sig->details.blinded_rsa_signature)
+    {
+      GNUNET_break (0);
+      return GNUNET_SYSERR;
+    }
+    denom_sig->cipher = TALER_DENOMINATION_RSA;
+    return GNUNET_OK;
+  // TODO: add case for Clause-Schnorr
+  default:
+    GNUNET_break (0);
+  }
+  return GNUNET_SYSERR;
+}
+
+
 void
 TALER_denom_pub_hash (const struct TALER_DenominationPublicKey *denom_pub,
                       struct TALER_DenominationHash *denom_hash)
diff --git a/src/util/taler-exchange-secmod-rsa.c b/src/util/taler-exchange-secmod-rsa.c
index 14709e2bd..028c54efe 100644
--- a/src/util/taler-exchange-secmod-rsa.c
+++ b/src/util/taler-exchange-secmod-rsa.c
@@ -208,10 +208,10 @@ struct WorkItem
   struct DenominationKey *dk;
 
   /**
-   * RSA signature over @e blinded_msg using @e dk. Result of doing the
-   * work. Initially NULL.
+   * Signature over @e blinded_msg using @e dk. Result of doing the
+   * work. Initially zero.
    */
-  struct GNUNET_CRYPTO_RsaSignature *rsa_signature;
+  struct TALER_BlindedDenominationSignature denom_sig;
 
   /**
    * Coin_ev value to sign.
@@ -424,11 +424,11 @@ sign_worker (void *cls)
                                    wi);
       work_counter--;
       GNUNET_assert (0 == pthread_mutex_unlock (&work_lock));
-      wi->rsa_signature
-        = GNUNET_CRYPTO_rsa_sign_blinded (
-            wi->dk->denom_priv.details.rsa_private_key,
-            wi->blinded_msg,
-            wi->blinded_msg_size);
+      GNUNET_break (GNUNET_OK ==
+                    TALER_denom_sign_blinded (&wi->denom_sig,
+                                              &wi->dk->denom_priv,
+                                              wi->blinded_msg,
+                                              wi->blinded_msg_size));
       /* put completed work into done queue */
       GNUNET_assert (0 == pthread_mutex_lock (&done_lock));
       GNUNET_CONTAINER_DLL_insert (done_head,
@@ -495,8 +495,8 @@ static void
 free_dk (struct DenominationKey *dk)
 {
   GNUNET_free (dk->filename);
-  GNUNET_CRYPTO_rsa_private_key_free (dk->denom_priv.details.rsa_private_key);
-  GNUNET_CRYPTO_rsa_public_key_free (dk->denom_pub.details.rsa_public_key);
+  TALER_denom_priv_free (&dk->denom_priv);
+  TALER_denom_pub_free (&dk->denom_pub);
   GNUNET_free (dk);
 }
 
@@ -584,7 +584,7 @@ handle_done (void *cls)
                                  done_tail,
                                  wi);
     GNUNET_assert (0 == pthread_mutex_unlock (&done_lock));
-    if (NULL == wi->rsa_signature)
+    if (TALER_DENOMINATION_INVALID == wi->denom_sig.cipher)
     {
       struct TALER_CRYPTO_SignFailure sf = {
         .header.size = htons (sizeof (sf)),
@@ -605,10 +605,10 @@ handle_done (void *cls)
       size_t buf_size;
       size_t tsize;
 
-      buf_size = GNUNET_CRYPTO_rsa_signature_encode (wi->rsa_signature,
-                                                     &buf);
-      GNUNET_CRYPTO_rsa_signature_free (wi->rsa_signature);
-      wi->rsa_signature = NULL;
+      buf_size = GNUNET_CRYPTO_rsa_signature_encode (
+        wi->denom_sig.details.blinded_rsa_signature,
+        &buf);
+      TALER_blinded_denom_sig_free (&wi->denom_sig);
       tsize = sizeof (*sr) + buf_size;
       GNUNET_assert (tsize < UINT16_MAX);
       sr = GNUNET_malloc (tsize);
@@ -844,19 +844,17 @@ setup_key (struct DenominationKey *dk,
   size_t buf_size;
   void *buf;
 
-  priv.cipher = TALER_DENOMINATION_RSA;
-  priv.details.rsa_private_key
-    = GNUNET_CRYPTO_rsa_private_key_create (denom->rsa_keysize);
-  if (NULL == priv.details.rsa_private_key)
+  if (GNUNET_OK !=
+      TALER_denom_priv_create (&priv,
+                               &pub,
+                               TALER_DENOMINATION_RSA,
+                               (unsigned int) denom->rsa_keysize))
   {
     GNUNET_break (0);
     GNUNET_SCHEDULER_shutdown ();
     global_ret = 40;
     return GNUNET_SYSERR;
   }
-  TALER_denom_priv_to_pub (&priv,
-                           0 /* FIXME-Oec */,
-                           &pub);
   buf_size = GNUNET_CRYPTO_rsa_private_key_encode (priv.details.rsa_private_key,
                                                    &buf);
   TALER_denom_pub_hash (&pub,
@@ -899,8 +897,8 @@ setup_key (struct DenominationKey *dk,
   {
     GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
                 "Duplicate private key created! Terminating.\n");
-    GNUNET_CRYPTO_rsa_private_key_free (dk->denom_priv.details.rsa_private_key);
-    GNUNET_CRYPTO_rsa_public_key_free (dk->denom_pub.details.rsa_public_key);
+    TALER_denom_priv_free (&dk->denom_priv);
+    TALER_denom_pub_free (&dk->denom_pub);
     GNUNET_free (dk->filename);
     GNUNET_free (dk);
     return GNUNET_SYSERR;
@@ -1261,7 +1259,7 @@ purge_key (struct DenominationKey *dk)
     dk->purge = true;
     return;
   }
-  GNUNET_CRYPTO_rsa_private_key_free (dk->denom_priv.details.rsa_private_key);
+  TALER_denom_priv_free (&dk->denom_priv);
   GNUNET_free (dk);
 }
 
@@ -1447,8 +1445,8 @@ parse_key (struct Denomination *denom,
                   "Duplicate private key %s detected in file `%s'. Skipping.\n",
                   GNUNET_h2s (&dk->h_denom_pub.hash),
                   filename);
-      GNUNET_CRYPTO_rsa_private_key_free (priv.details.rsa_private_key);
-      GNUNET_CRYPTO_rsa_public_key_free (pub.details.rsa_public_key);
+      TALER_denom_priv_free (&priv);
+      TALER_denom_pub_free (&pub);
       GNUNET_free (dk);
       return;
     }
diff --git a/src/util/test_crypto.c b/src/util/test_crypto.c
index 653df86f7..416ca5e2d 100644
--- a/src/util/test_crypto.c
+++ b/src/util/test_crypto.c
@@ -92,12 +92,11 @@ test_planchets (void)
   struct TALER_FreshCoin coin;
   struct TALER_CoinPubHash c_hash;
 
-  dk_priv.cipher = TALER_DENOMINATION_RSA;
-  dk_priv.details.rsa_private_key
-    = GNUNET_CRYPTO_rsa_private_key_create (1024);
-  TALER_denom_priv_to_pub (&dk_priv,
-                           0,
-                           &dk_pub);
+  GNUNET_assert (GNUNET_OK ==
+                 TALER_denom_priv_create (&dk_priv,
+                                          &dk_pub,
+                                          TALER_DENOMINATION_RSA,
+                                          1024));
   TALER_planchet_setup_random (&ps);
   GNUNET_assert (GNUNET_OK ==
                  TALER_planchet_prepare (&dk_pub,