diff --git a/src/gtest/main.cpp b/src/gtest/main.cpp
index d1ffa628a..a0a2e0042 100644
--- a/src/gtest/main.cpp
+++ b/src/gtest/main.cpp
@@ -4,6 +4,8 @@
 
 #include "libsnark/common/default_types/r1cs_ppzksnark_pp.hpp"
 #include "libsnark/zk_proof_systems/ppzksnark/r1cs_ppzksnark/r1cs_ppzksnark.hpp"
+#include "zcash/JoinSplit.hpp"
+#include "util.h"
 
 struct ECCryptoClosure
 {
@@ -12,11 +14,16 @@ struct ECCryptoClosure
 
 ECCryptoClosure instance_of_eccryptoclosure;
 
+ZCJoinSplit* params;
+
 int main(int argc, char **argv) {
   assert(init_and_check_sodium() != -1);
   libsnark::default_r1cs_ppzksnark_pp::init_public_params();
   libsnark::inhibit_profiling_info = true;
   libsnark::inhibit_profiling_counters = true;
+  boost::filesystem::path pk_path = ZC_GetParamsDir() / "sprout-proving.key";
+  boost::filesystem::path vk_path = ZC_GetParamsDir() / "sprout-verifying.key";
+  params = ZCJoinSplit::Prepared(vk_path.string(), pk_path.string());
   
   testing::InitGoogleTest(&argc, argv);
   return RUN_ALL_TESTS();
diff --git a/src/gtest/test_joinsplit.cpp b/src/gtest/test_joinsplit.cpp
index 17ac7ecb2..986592e89 100644
--- a/src/gtest/test_joinsplit.cpp
+++ b/src/gtest/test_joinsplit.cpp
@@ -5,6 +5,7 @@
 #include <boost/foreach.hpp>
 
 #include "zcash/prf.h"
+#include "util.h"
 
 #include "zcash/JoinSplit.hpp"
 #include "zcash/Note.hpp"
@@ -13,6 +14,8 @@
 
 using namespace libzcash;
 
+extern ZCJoinSplit* params;
+
 void test_full_api(ZCJoinSplit* js)
 {
     // Create verification context.
@@ -219,8 +222,6 @@ void invokeAPIFailure(
 
 TEST(joinsplit, h_sig)
 {
-    auto js = ZCJoinSplit::Unopened();
-
 /*
 // by Taylor Hornby
 
@@ -284,7 +285,7 @@ for test_input in TEST_VECTORS:
     };
 
     BOOST_FOREACH(std::vector<std::string>& v, tests) {
-        auto expected = js->h_sig(
+        auto expected = ZCJoinSplit::h_sig(
             uint256S(v[0]),
             {uint256S(v[1]), uint256S(v[2])},
             uint256S(v[3])
@@ -292,8 +293,6 @@ for test_input in TEST_VECTORS:
 
         EXPECT_EQ(expected, uint256S(v[4]));
     }
-
-    delete js;
 }
 
 void increment_note_witnesses(
@@ -311,8 +310,6 @@ void increment_note_witnesses(
 
 TEST(joinsplit, full_api_test)
 {
-    auto js = ZCJoinSplit::Generate();
-
     {
         std::vector<ZCIncrementalWitness> witnesses;
         ZCIncrementalMerkleTree tree;
@@ -331,7 +328,7 @@ TEST(joinsplit, full_api_test)
         increment_note_witnesses(note5.cm(), witnesses, tree);
 
         // Should work
-        invokeAPI(js,
+        invokeAPI(params,
         {
             JSInput(),
             JSInput()
@@ -345,7 +342,7 @@ TEST(joinsplit, full_api_test)
         tree.root());
 
         // lhs > MAX_MONEY
-        invokeAPIFailure(js,
+        invokeAPIFailure(params,
         {
             JSInput(),
             JSInput()
@@ -360,7 +357,7 @@ TEST(joinsplit, full_api_test)
         "nonsensical vpub_old value");
 
         // rhs > MAX_MONEY
-        invokeAPIFailure(js,
+        invokeAPIFailure(params,
         {
             JSInput(),
             JSInput()
@@ -375,7 +372,7 @@ TEST(joinsplit, full_api_test)
         "nonsensical vpub_new value");
 
         // input witness for the wrong element
-        invokeAPIFailure(js,
+        invokeAPIFailure(params,
         {
             JSInput(witnesses[0], note1, sk),
             JSInput()
@@ -391,7 +388,7 @@ TEST(joinsplit, full_api_test)
 
         // input witness doesn't match up with
         // real root
-        invokeAPIFailure(js,
+        invokeAPIFailure(params,
         {
             JSInput(witnesses[1], note1, sk),
             JSInput()
@@ -406,7 +403,7 @@ TEST(joinsplit, full_api_test)
         "joinsplit not anchored to the correct root");
 
         // input is in the tree now! this should work
-        invokeAPI(js,
+        invokeAPI(params,
         {
             JSInput(witnesses[1], note1, sk),
             JSInput()
@@ -420,7 +417,7 @@ TEST(joinsplit, full_api_test)
         tree.root());
 
         // Wrong secret key
-        invokeAPIFailure(js,
+        invokeAPIFailure(params,
         {
             JSInput(witnesses[1], note1, SpendingKey::random()),
             JSInput()
@@ -435,7 +432,7 @@ TEST(joinsplit, full_api_test)
         "input note not authorized to spend with given key");
 
         // Absurd input value
-        invokeAPIFailure(js,
+        invokeAPIFailure(params,
         {
             JSInput(witnesses[3], note3, sk),
             JSInput()
@@ -450,7 +447,7 @@ TEST(joinsplit, full_api_test)
         "nonsensical input note value");
 
         // Absurd total input value
-        invokeAPIFailure(js,
+        invokeAPIFailure(params,
         {
             JSInput(witnesses[4], note4, sk),
             JSInput(witnesses[5], note5, sk)
@@ -465,7 +462,7 @@ TEST(joinsplit, full_api_test)
         "nonsensical left hand size of joinsplit balance");
 
         // Absurd output value
-        invokeAPIFailure(js,
+        invokeAPIFailure(params,
         {
             JSInput(),
             JSInput()
@@ -480,7 +477,7 @@ TEST(joinsplit, full_api_test)
         "nonsensical output value");
 
         // Absurd total output value
-        invokeAPIFailure(js,
+        invokeAPIFailure(params,
         {
             JSInput(),
             JSInput()
@@ -495,7 +492,7 @@ TEST(joinsplit, full_api_test)
         "nonsensical right hand side of joinsplit balance");
 
         // Absurd total output value
-        invokeAPIFailure(js,
+        invokeAPIFailure(params,
         {
             JSInput(),
             JSInput()
@@ -510,22 +507,7 @@ TEST(joinsplit, full_api_test)
         "invalid joinsplit balance");
     }
 
-    test_full_api(js);
-
-    js->saveProvingKey("./zcashTest.pk");
-    js->saveVerifyingKey("./zcashTest.vk");
-
-    delete js;
-
-    js = ZCJoinSplit::Unopened();
-
-    js->setProvingKeyPath("./zcashTest.pk");
-    js->loadProvingKey();
-    js->loadVerifyingKey("./zcashTest.vk");
-
-    test_full_api(js);
-
-    delete js;
+    test_full_api(params);
 }
 
 TEST(joinsplit, note_plaintexts)
diff --git a/src/gtest/utils.cpp b/src/gtest/utils.cpp
index cf025162c..527e613e2 100644
--- a/src/gtest/utils.cpp
+++ b/src/gtest/utils.cpp
@@ -1,7 +1,3 @@
-#include "zcash/JoinSplit.hpp"
-
-ZCJoinSplit* params = ZCJoinSplit::Unopened();
-
 int GenZero(int n)
 {
     return 0;
diff --git a/src/init.cpp b/src/init.cpp
index 59a59524d..e8ab677b0 100644
--- a/src/init.cpp
+++ b/src/init.cpp
@@ -688,18 +688,14 @@ static void ZC_LoadParams()
         return;
     }
 
-    pzcashParams = ZCJoinSplit::Unopened();
-
     LogPrintf("Loading verifying key from %s\n", vk_path.string().c_str());
     gettimeofday(&tv_start, 0);
 
-    pzcashParams->loadVerifyingKey(vk_path.string());
+    pzcashParams = ZCJoinSplit::Prepared(vk_path.string(), pk_path.string());
 
     gettimeofday(&tv_end, 0);
     elapsed = float(tv_end.tv_sec-tv_start.tv_sec) + (tv_end.tv_usec-tv_start.tv_usec)/float(1000000);
     LogPrintf("Loaded verifying key in %fs seconds.\n", elapsed);
-
-    pzcashParams->setProvingKeyPath(pk_path.string());
 }
 
 bool AppInitServers(boost::thread_group& threadGroup)
diff --git a/src/primitives/transaction.cpp b/src/primitives/transaction.cpp
index f6236a2f8..6aa7949b2 100644
--- a/src/primitives/transaction.cpp
+++ b/src/primitives/transaction.cpp
@@ -20,9 +20,6 @@ JSDescription::JSDescription(ZCJoinSplit& params,
 {
     boost::array<libzcash::Note, ZC_NUM_JS_OUTPUTS> notes;
 
-    if (computeProof) {
-        params.loadProvingKey();
-    }
     proof = params.prove(
         inputs,
         outputs,
diff --git a/src/snark/src/zk_proof_systems/ppzksnark/r1cs_ppzksnark/r1cs_ppzksnark.hpp b/src/snark/src/zk_proof_systems/ppzksnark/r1cs_ppzksnark/r1cs_ppzksnark.hpp
index 36f6c1499..96bc36504 100644
--- a/src/snark/src/zk_proof_systems/ppzksnark/r1cs_ppzksnark/r1cs_ppzksnark.hpp
+++ b/src/snark/src/zk_proof_systems/ppzksnark/r1cs_ppzksnark/r1cs_ppzksnark.hpp
@@ -397,6 +397,12 @@ r1cs_ppzksnark_proof<ppT> r1cs_ppzksnark_prover(const r1cs_ppzksnark_proving_key
                                                 const r1cs_ppzksnark_auxiliary_input<ppT> &auxiliary_input,
                                                 const r1cs_ppzksnark_constraint_system<ppT> &constraint_system);
 
+template<typename ppT>
+r1cs_ppzksnark_proof<ppT> r1cs_ppzksnark_prover_streaming(std::ifstream &proving_key_file,
+                                                          const r1cs_ppzksnark_primary_input<ppT> &primary_input,
+                                                          const r1cs_ppzksnark_auxiliary_input<ppT> &auxiliary_input,
+                                                          const r1cs_ppzksnark_constraint_system<ppT> &constraint_system);
+
 /*
  Below are four variants of verifier algorithm for the R1CS ppzkSNARK.
 
diff --git a/src/snark/src/zk_proof_systems/ppzksnark/r1cs_ppzksnark/r1cs_ppzksnark.tcc b/src/snark/src/zk_proof_systems/ppzksnark/r1cs_ppzksnark/r1cs_ppzksnark.tcc
index aeb2bbb85..84db9fc1a 100644
--- a/src/snark/src/zk_proof_systems/ppzksnark/r1cs_ppzksnark/r1cs_ppzksnark.tcc
+++ b/src/snark/src/zk_proof_systems/ppzksnark/r1cs_ppzksnark/r1cs_ppzksnark.tcc
@@ -431,6 +431,92 @@ r1cs_ppzksnark_keypair<ppT> r1cs_ppzksnark_generator(
     return r1cs_ppzksnark_keypair<ppT>(std::move(pk), std::move(vk));
 }
 
+template <typename ppT, typename T1, typename T2>
+knowledge_commitment<T1, T2> r1cs_compute_proof_kc(const qap_witness<Fr<ppT> > &qap_wit,
+                                                   const knowledge_commitment_vector<T1, T2> &kcv,
+                                                   const Fr<ppT>  &zk_shift)
+{
+    knowledge_commitment<T1, T2> returnval = kcv[0] + (zk_shift * kcv[qap_wit.num_variables()+1]);
+
+#ifdef DEBUG
+    assert(kcv.domain_size() == qap_wit.num_variables()+2);
+#endif
+
+#ifdef MULTICORE
+    const size_t chunks = omp_get_max_threads(); // to override, set OMP_NUM_THREADS env var or call omp_set_num_threads()
+#else
+    const size_t chunks = 1;
+#endif
+
+    returnval = returnval + kc_multi_exp_with_mixed_addition<T1, T2, Fr<ppT> >(
+        kcv,
+        1,
+        1 + qap_wit.num_variables(),
+        qap_wit.coefficients_for_ABCs.begin(),
+        qap_wit.coefficients_for_ABCs.begin()+qap_wit.num_variables(),
+        chunks,
+        true
+    );
+
+    return returnval;
+}
+
+
+
+template <typename ppT>
+G1<ppT> r1cs_compute_proof_K(const qap_witness<Fr<ppT>> &qap_wit, const G1_vector<ppT> &K_query, const G1<ppT> &zk_shift)
+{
+#ifdef DEBUG
+    assert(K_query.size() == qap_wit.num_variables()+4);
+#endif
+
+#ifdef MULTICORE
+    const size_t chunks = omp_get_max_threads(); // to override, set OMP_NUM_THREADS env var or call omp_set_num_threads()
+#else
+    const size_t chunks = 1;
+#endif
+
+    G1<ppT> g_K = K_query[0] + zk_shift;
+    g_K = g_K + multi_exp_with_mixed_addition<G1<ppT>, Fr<ppT> >(
+        K_query.begin()+1,
+        K_query.begin()+1+qap_wit.num_variables(),
+        qap_wit.coefficients_for_ABCs.begin(),
+        qap_wit.coefficients_for_ABCs.begin()+qap_wit.num_variables(),
+        chunks,
+        true
+    );
+
+    return g_K;
+}
+
+
+template <typename ppT>
+G1<ppT> r1cs_compute_proof_H(const qap_witness<Fr<ppT> > &qap_wit, const G1_vector<ppT> &H_query)
+{
+    G1<ppT> g_H = G1<ppT>::zero();
+
+#ifdef DEBUG
+    assert(H_query.size() == qap_wit.degree()+1);
+#endif
+
+#ifdef MULTICORE
+    const size_t chunks = omp_get_max_threads(); // to override, set OMP_NUM_THREADS env var or call omp_set_num_threads()
+#else
+    const size_t chunks = 1;
+#endif
+
+    g_H = g_H + multi_exp<G1<ppT>, Fr<ppT> >(
+        H_query.begin(),
+        H_query.begin()+qap_wit.degree()+1,
+        qap_wit.coefficients_for_H.begin(),
+        qap_wit.coefficients_for_H.begin()+qap_wit.degree()+1,
+        chunks,
+        true
+    );
+
+    return g_H;
+}
+
 template <typename ppT>
 r1cs_ppzksnark_proof<ppT> r1cs_ppzksnark_prover(const r1cs_ppzksnark_proving_key<ppT> &pk,
                                                 const r1cs_ppzksnark_primary_input<ppT> &primary_input,
@@ -457,67 +543,36 @@ r1cs_ppzksnark_proof<ppT> r1cs_ppzksnark_prover(const r1cs_ppzksnark_proving_key
     assert(qap_inst.is_satisfied(qap_wit));
 #endif
 
-    knowledge_commitment<G1<ppT>, G1<ppT> > g_A = pk.A_query[0] + qap_wit.d1*pk.A_query[qap_wit.num_variables()+1];
-    knowledge_commitment<G2<ppT>, G1<ppT> > g_B = pk.B_query[0] + qap_wit.d2*pk.B_query[qap_wit.num_variables()+1];
-    knowledge_commitment<G1<ppT>, G1<ppT> > g_C = pk.C_query[0] + qap_wit.d3*pk.C_query[qap_wit.num_variables()+1];
-
-    G1<ppT> g_H = G1<ppT>::zero();
-    G1<ppT> g_K = (pk.K_query[0] +
-                   qap_wit.d1*pk.K_query[qap_wit.num_variables()+1] +
-                   qap_wit.d2*pk.K_query[qap_wit.num_variables()+2] +
-                   qap_wit.d3*pk.K_query[qap_wit.num_variables()+3]);
-
 #ifdef DEBUG
     for (size_t i = 0; i < qap_wit.num_inputs() + 1; ++i)
     {
         assert(pk.A_query[i].g == G1<ppT>::zero());
     }
-    assert(pk.A_query.domain_size() == qap_wit.num_variables()+2);
-    assert(pk.B_query.domain_size() == qap_wit.num_variables()+2);
-    assert(pk.C_query.domain_size() == qap_wit.num_variables()+2);
-    assert(pk.H_query.size() == qap_wit.degree()+1);
-    assert(pk.K_query.size() == qap_wit.num_variables()+4);
-#endif
-
-#ifdef MULTICORE
-    const size_t chunks = omp_get_max_threads(); // to override, set OMP_NUM_THREADS env var or call omp_set_num_threads()
-#else
-    const size_t chunks = 1;
 #endif
 
     enter_block("Compute the proof");
 
     enter_block("Compute answer to A-query", false);
-    g_A = g_A + kc_multi_exp_with_mixed_addition<G1<ppT>, G1<ppT>, Fr<ppT> >(pk.A_query,
-                                                                             1, 1+qap_wit.num_variables(),
-                                                                             qap_wit.coefficients_for_ABCs.begin(), qap_wit.coefficients_for_ABCs.begin()+qap_wit.num_variables(),
-                                                                             chunks, true);
+    auto g_A = r1cs_compute_proof_kc<ppT, G1<ppT>, G1<ppT> >(qap_wit, pk.A_query, qap_wit.d1);
     leave_block("Compute answer to A-query", false);
 
     enter_block("Compute answer to B-query", false);
-    g_B = g_B + kc_multi_exp_with_mixed_addition<G2<ppT>, G1<ppT>, Fr<ppT> >(pk.B_query,
-                                                                             1, 1+qap_wit.num_variables(),
-                                                                             qap_wit.coefficients_for_ABCs.begin(), qap_wit.coefficients_for_ABCs.begin()+qap_wit.num_variables(),
-                                                                             chunks, true);
+    auto g_B = r1cs_compute_proof_kc<ppT, G2<ppT>, G1<ppT> >(qap_wit, pk.B_query, qap_wit.d2);
     leave_block("Compute answer to B-query", false);
 
     enter_block("Compute answer to C-query", false);
-    g_C = g_C + kc_multi_exp_with_mixed_addition<G1<ppT>, G1<ppT>, Fr<ppT> >(pk.C_query,
-                                                                             1, 1+qap_wit.num_variables(),
-                                                                             qap_wit.coefficients_for_ABCs.begin(), qap_wit.coefficients_for_ABCs.begin()+qap_wit.num_variables(),
-                                                                             chunks, true);
+    auto g_C = r1cs_compute_proof_kc<ppT, G1<ppT>, G1<ppT> >(qap_wit, pk.C_query, qap_wit.d3);
     leave_block("Compute answer to C-query", false);
 
     enter_block("Compute answer to H-query", false);
-    g_H = g_H + multi_exp<G1<ppT>, Fr<ppT> >(pk.H_query.begin(), pk.H_query.begin()+qap_wit.degree()+1,
-                                             qap_wit.coefficients_for_H.begin(), qap_wit.coefficients_for_H.begin()+qap_wit.degree()+1,
-                                             chunks, true);
+    auto g_H = r1cs_compute_proof_H<ppT>(qap_wit, pk.H_query);
     leave_block("Compute answer to H-query", false);
 
     enter_block("Compute answer to K-query", false);
-    g_K = g_K + multi_exp_with_mixed_addition<G1<ppT>, Fr<ppT> >(pk.K_query.begin()+1, pk.K_query.begin()+1+qap_wit.num_variables(),
-                                                                 qap_wit.coefficients_for_ABCs.begin(), qap_wit.coefficients_for_ABCs.begin()+qap_wit.num_variables(),
-                                                                 chunks, true);
+    G1<ppT> zk_shift = qap_wit.d1*pk.K_query[qap_wit.num_variables()+1] +
+                       qap_wit.d2*pk.K_query[qap_wit.num_variables()+2] +
+                       qap_wit.d3*pk.K_query[qap_wit.num_variables()+3];
+    G1<ppT> g_K = r1cs_compute_proof_K<ppT>(qap_wit, pk.K_query, zk_shift);
     leave_block("Compute answer to K-query", false);
 
     leave_block("Compute the proof");
@@ -525,7 +580,76 @@ r1cs_ppzksnark_proof<ppT> r1cs_ppzksnark_prover(const r1cs_ppzksnark_proving_key
     leave_block("Call to r1cs_ppzksnark_prover");
 
     r1cs_ppzksnark_proof<ppT> proof = r1cs_ppzksnark_proof<ppT>(std::move(g_A), std::move(g_B), std::move(g_C), std::move(g_H), std::move(g_K));
-    //proof.print_size();
+
+    return proof;
+}
+
+template <typename ppT>
+r1cs_ppzksnark_proof<ppT> r1cs_ppzksnark_prover_streaming(std::ifstream &proving_key_file,
+                                                          const r1cs_ppzksnark_primary_input<ppT> &primary_input,
+                                                          const r1cs_ppzksnark_auxiliary_input<ppT> &auxiliary_input,
+                                                          const r1cs_ppzksnark_constraint_system<ppT> &constraint_system)
+{
+    enter_block("Call to r1cs_ppzksnark_prover_streaming");
+
+    const Fr<ppT> d1 = Fr<ppT>::random_element(),
+        d2 = Fr<ppT>::random_element(),
+        d3 = Fr<ppT>::random_element();
+
+    enter_block("Compute the polynomial H");
+    const qap_witness<Fr<ppT> > qap_wit = r1cs_to_qap_witness_map(constraint_system, primary_input, auxiliary_input, d1, d2, d3);
+    leave_block("Compute the polynomial H");
+
+    enter_block("Compute the proof");
+
+    r1cs_ppzksnark_proof<ppT> proof;
+
+    enter_block("Compute answer to A-query", false);
+    {
+        knowledge_commitment_vector<G1<ppT>, G1<ppT> > A_query;
+        proving_key_file >> A_query;
+        proof.g_A = r1cs_compute_proof_kc<ppT, G1<ppT>, G1<ppT> >(qap_wit, A_query, qap_wit.d1);
+    }
+    leave_block("Compute answer to A-query", false);
+
+    enter_block("Compute answer to B-query", false);
+    {
+        knowledge_commitment_vector<G2<ppT>, G1<ppT> > B_query;
+        proving_key_file >> B_query;
+        proof.g_B = r1cs_compute_proof_kc<ppT, G2<ppT>, G1<ppT> >(qap_wit, B_query, qap_wit.d2);
+    }
+    leave_block("Compute answer to B-query", false);
+
+    enter_block("Compute answer to C-query", false);
+    {
+        knowledge_commitment_vector<G1<ppT>, G1<ppT> > C_query;
+        proving_key_file >> C_query;
+        proof.g_C = r1cs_compute_proof_kc<ppT, G1<ppT>, G1<ppT> >(qap_wit, C_query, qap_wit.d3);
+    }
+    leave_block("Compute answer to C-query", false);
+
+    enter_block("Compute answer to H-query", false);
+    {
+        G1_vector<ppT> H_query;
+        proving_key_file >> H_query;
+        proof.g_H = r1cs_compute_proof_H<ppT>(qap_wit, H_query);
+    }
+    leave_block("Compute answer to H-query", false);
+
+    enter_block("Compute answer to K-query", false);
+    {
+        G1_vector<ppT> K_query;
+        proving_key_file >> K_query;
+        G1<ppT> zk_shift = qap_wit.d1*K_query[qap_wit.num_variables()+1] +
+                           qap_wit.d2*K_query[qap_wit.num_variables()+2] +
+                           qap_wit.d3*K_query[qap_wit.num_variables()+3];
+        proof.g_K = r1cs_compute_proof_K<ppT>(qap_wit, K_query, zk_shift);
+    }
+    leave_block("Compute answer to K-query", false);
+
+    leave_block("Compute the proof");
+
+    leave_block("Call to r1cs_ppzksnark_prover_streaming");
 
     return proof;
 }
diff --git a/src/test/rpc_wallet_tests.cpp b/src/test/rpc_wallet_tests.cpp
index 6017333b4..e444eb2a5 100644
--- a/src/test/rpc_wallet_tests.cpp
+++ b/src/test/rpc_wallet_tests.cpp
@@ -1175,7 +1175,7 @@ BOOST_AUTO_TEST_CASE(rpc_z_sendmany_internals)
         try {
             proxy.perform_joinsplit(info);
         } catch (const std::runtime_error & e) {
-            BOOST_CHECK( string(e.what()).find("JoinSplit verifying key not loaded")!= string::npos);
+            BOOST_CHECK( string(e.what()).find("error verifying joinsplit")!= string::npos);
         }
     }
 
@@ -1372,7 +1372,7 @@ BOOST_AUTO_TEST_CASE(rpc_z_shieldcoinbase_internals)
         try {
             proxy.perform_joinsplit(info);
         } catch (const std::runtime_error & e) {
-            BOOST_CHECK( string(e.what()).find("JoinSplit verifying key not loaded")!= string::npos);
+            BOOST_CHECK( string(e.what()).find("error verifying joinsplit")!= string::npos);
         }
     }
 
diff --git a/src/test/test_bitcoin.cpp b/src/test/test_bitcoin.cpp
index 5c701c5cc..0a39f2944 100644
--- a/src/test/test_bitcoin.cpp
+++ b/src/test/test_bitcoin.cpp
@@ -30,20 +30,30 @@ ZCJoinSplit *pzcashParams;
 extern bool fPrintToConsole;
 extern void noui_connect();
 
+JoinSplitTestingSetup::JoinSplitTestingSetup()
+{
+    boost::filesystem::path pk_path = ZC_GetParamsDir() / "sprout-proving.key";
+    boost::filesystem::path vk_path = ZC_GetParamsDir() / "sprout-verifying.key";
+    pzcashParams = ZCJoinSplit::Prepared(vk_path.string(), pk_path.string());
+}
+
+JoinSplitTestingSetup::~JoinSplitTestingSetup()
+{
+    delete pzcashParams;
+}
+
 BasicTestingSetup::BasicTestingSetup()
 {
-        assert(init_and_check_sodium() != -1);
-        ECC_Start();
-        pzcashParams = ZCJoinSplit::Unopened();
-        SetupEnvironment();
-        fPrintToDebugLog = false; // don't want to write to debug.log file
-        fCheckBlockIndex = true;
-        SelectParams(CBaseChainParams::MAIN);
+    assert(init_and_check_sodium() != -1);
+    ECC_Start();
+    SetupEnvironment();
+    fPrintToDebugLog = false; // don't want to write to debug.log file
+    fCheckBlockIndex = true;
+    SelectParams(CBaseChainParams::MAIN);
 }
 BasicTestingSetup::~BasicTestingSetup()
 {
-        ECC_Stop();
-        delete pzcashParams;
+    ECC_Stop();
 }
 
 TestingSetup::TestingSetup()
diff --git a/src/test/test_bitcoin.h b/src/test/test_bitcoin.h
index 205e5b5c4..d1c426373 100644
--- a/src/test/test_bitcoin.h
+++ b/src/test/test_bitcoin.h
@@ -17,11 +17,17 @@ struct BasicTestingSetup {
     ~BasicTestingSetup();
 };
 
+// Setup w.r.t. zk-SNARK API
+struct JoinSplitTestingSetup: public BasicTestingSetup {
+    JoinSplitTestingSetup();
+    ~JoinSplitTestingSetup();
+};
+
 /** Testing setup that configures a complete environment.
  * Included are data directory, coins database, script check threads
  * and wallet (if enabled) setup.
  */
-struct TestingSetup: public BasicTestingSetup {
+struct TestingSetup: public JoinSplitTestingSetup {
     CCoinsViewDB *pcoinsdbview;
     boost::filesystem::path pathTemp;
     boost::thread_group threadGroup;
diff --git a/src/test/transaction_tests.cpp b/src/test/transaction_tests.cpp
index 3fa691a94..6b207f643 100644
--- a/src/test/transaction_tests.cpp
+++ b/src/test/transaction_tests.cpp
@@ -6,6 +6,7 @@
 #include "data/tx_valid.json.h"
 #include "test/test_bitcoin.h"
 
+#include "init.h"
 #include "clientversion.h"
 #include "consensus/validation.h"
 #include "core_io.h"
@@ -85,7 +86,7 @@ string FormatScriptFlags(unsigned int flags)
     return ret.substr(0, ret.size() - 1);
 }
 
-BOOST_FIXTURE_TEST_SUITE(transaction_tests, BasicTestingSetup)
+BOOST_FIXTURE_TEST_SUITE(transaction_tests, JoinSplitTestingSetup)
 
 BOOST_AUTO_TEST_CASE(tx_valid)
 {
@@ -326,9 +327,6 @@ BOOST_AUTO_TEST_CASE(test_basic_joinsplit_verification)
     // Also, it's generally libzcash's job to ensure the
     // integrity of the scheme through its own tests.
 
-    // construct the r1cs keypair
-    auto p = ZCJoinSplit::Generate();
-
     // construct a merkle tree
     ZCIncrementalMerkleTree merkleTree;
 
@@ -362,8 +360,8 @@ BOOST_AUTO_TEST_CASE(test_basic_joinsplit_verification)
     auto verifier = libzcash::ProofVerifier::Strict();
 
     {
-        JSDescription jsdesc(*p, pubKeyHash, rt, inputs, outputs, 0, 0);
-        BOOST_CHECK(jsdesc.Verify(*p, verifier, pubKeyHash));
+        JSDescription jsdesc(*pzcashParams, pubKeyHash, rt, inputs, outputs, 0, 0);
+        BOOST_CHECK(jsdesc.Verify(*pzcashParams, verifier, pubKeyHash));
 
         CDataStream ss(SER_DISK, CLIENT_VERSION);
         ss << jsdesc;
@@ -372,20 +370,20 @@ BOOST_AUTO_TEST_CASE(test_basic_joinsplit_verification)
         ss >> jsdesc_deserialized;
 
         BOOST_CHECK(jsdesc_deserialized == jsdesc);
-        BOOST_CHECK(jsdesc_deserialized.Verify(*p, verifier, pubKeyHash));
+        BOOST_CHECK(jsdesc_deserialized.Verify(*pzcashParams, verifier, pubKeyHash));
     }
 
     {
         // Ensure that the balance equation is working.
-        BOOST_CHECK_THROW(JSDescription(*p, pubKeyHash, rt, inputs, outputs, 10, 0), std::invalid_argument);
-        BOOST_CHECK_THROW(JSDescription(*p, pubKeyHash, rt, inputs, outputs, 0, 10), std::invalid_argument);
+        BOOST_CHECK_THROW(JSDescription(*pzcashParams, pubKeyHash, rt, inputs, outputs, 10, 0), std::invalid_argument);
+        BOOST_CHECK_THROW(JSDescription(*pzcashParams, pubKeyHash, rt, inputs, outputs, 0, 10), std::invalid_argument);
     }
 
     {
         // Ensure that it won't verify if the root is changed.
-        auto test = JSDescription(*p, pubKeyHash, rt, inputs, outputs, 0, 0);
+        auto test = JSDescription(*pzcashParams, pubKeyHash, rt, inputs, outputs, 0, 0);
         test.anchor = GetRandHash();
-        BOOST_CHECK(!test.Verify(*p, verifier, pubKeyHash));
+        BOOST_CHECK(!test.Verify(*pzcashParams, verifier, pubKeyHash));
     }
 }
 
diff --git a/src/wallet/rpcwallet.cpp b/src/wallet/rpcwallet.cpp
index 843af53bd..034147f42 100644
--- a/src/wallet/rpcwallet.cpp
+++ b/src/wallet/rpcwallet.cpp
@@ -2543,12 +2543,6 @@ UniValue zc_benchmark(const UniValue& params, bool fHelp)
 
     std::vector<double> sample_times;
 
-    if (benchmarktype == "createjoinsplit") {
-        /* Load the proving now key so that it doesn't happen as part of the
-         * first joinsplit. */
-        pzcashParams->loadProvingKey();
-    }
-
     JSDescription samplejoinsplit;
 
     if (benchmarktype == "verifyjoinsplit") {
diff --git a/src/zcash/CreateJoinSplit.cpp b/src/zcash/CreateJoinSplit.cpp
index ea2d59c9e..7253e9568 100644
--- a/src/zcash/CreateJoinSplit.cpp
+++ b/src/zcash/CreateJoinSplit.cpp
@@ -13,10 +13,8 @@ int main(int argc, char **argv)
 {
     libsnark::start_profiling();
 
-    auto p = ZCJoinSplit::Unopened();
-    p->loadVerifyingKey((ZC_GetParamsDir() / "sprout-verifying.key").string());
-    p->setProvingKeyPath((ZC_GetParamsDir() / "sprout-proving.key").string());
-    p->loadProvingKey();
+    auto p = ZCJoinSplit::Prepared((ZC_GetParamsDir() / "sprout-verifying.key").string(),
+                                   (ZC_GetParamsDir() / "sprout-proving.key").string());
 
     // construct a proof.
 
@@ -32,4 +30,6 @@ int main(int argc, char **argv)
                              0,
                              0);
     }
+
+    delete p; // not that it matters
 }
diff --git a/src/zcash/GenerateParams.cpp b/src/zcash/GenerateParams.cpp
index eadfe7b18..8ca2d7814 100644
--- a/src/zcash/GenerateParams.cpp
+++ b/src/zcash/GenerateParams.cpp
@@ -18,13 +18,7 @@ int main(int argc, char **argv)
     std::string vkFile = argv[2];
     std::string r1csFile = argv[3];
 
-    auto p = ZCJoinSplit::Generate();
-
-    p->saveProvingKey(pkFile);
-    p->saveVerifyingKey(vkFile);
-    p->saveR1CS(r1csFile);
-
-    delete p;
+    ZCJoinSplit::Generate(r1csFile, vkFile, pkFile);
 
     return 0;
 }
diff --git a/src/zcash/JoinSplit.cpp b/src/zcash/JoinSplit.cpp
index 590700cd9..d71dbd0ee 100644
--- a/src/zcash/JoinSplit.cpp
+++ b/src/zcash/JoinSplit.cpp
@@ -14,7 +14,7 @@
 #include "libsnark/zk_proof_systems/ppzksnark/r1cs_ppzksnark/r1cs_ppzksnark.hpp"
 #include "libsnark/gadgetlib1/gadgets/hashes/sha256/sha256_gadget.hpp"
 #include "libsnark/gadgetlib1/gadgets/merkle_tree/merkle_tree_check_read_gadget.hpp"
-
+#include "tinyformat.h"
 #include "sync.h"
 #include "amount.h"
 
@@ -28,7 +28,7 @@ CCriticalSection cs_ParamsIO;
 CCriticalSection cs_LoadKeys;
 
 template<typename T>
-void saveToFile(std::string path, T& obj) {
+void saveToFile(const std::string path, T& obj) {
     LOCK(cs_ParamsIO);
 
     std::stringstream ss;
@@ -42,14 +42,14 @@ void saveToFile(std::string path, T& obj) {
 }
 
 template<typename T>
-void loadFromFile(std::string path, boost::optional<T>& objIn) {
+void loadFromFile(const std::string path, T& objIn) {
     LOCK(cs_ParamsIO);
 
     std::stringstream ss;
     std::ifstream fh(path, std::ios::binary);
 
     if(!fh.is_open()) {
-        throw std::runtime_error((boost::format("could not load param file at %s") % path).str());
+        throw std::runtime_error(strprintf("could not load param file at %s", path));
     }
 
     ss << fh.rdbuf();
@@ -69,77 +69,33 @@ public:
     typedef default_r1cs_ppzksnark_pp ppzksnark_ppT;
     typedef Fr<ppzksnark_ppT> FieldT;
 
-    boost::optional<r1cs_ppzksnark_proving_key<ppzksnark_ppT>> pk;
-    boost::optional<r1cs_ppzksnark_verification_key<ppzksnark_ppT>> vk;
-    boost::optional<r1cs_ppzksnark_processed_verification_key<ppzksnark_ppT>> vk_precomp;
-    boost::optional<std::string> pkPath;
+    r1cs_ppzksnark_verification_key<ppzksnark_ppT> vk;
+    r1cs_ppzksnark_processed_verification_key<ppzksnark_ppT> vk_precomp;
+    std::string pkPath;
 
-    JoinSplitCircuit() {}
+    JoinSplitCircuit(const std::string vkPath, const std::string pkPath) : pkPath(pkPath) {
+        loadFromFile(vkPath, vk);
+        vk_precomp = r1cs_ppzksnark_verifier_process_vk(vk);
+    }
     ~JoinSplitCircuit() {}
 
-    void setProvingKeyPath(std::string path) {
-        pkPath = path;
-    }
-
-    void loadProvingKey() {
-        LOCK(cs_LoadKeys);
-
-        if (!pk) {
-            if (!pkPath) {
-                throw std::runtime_error("proving key path unknown");
-            }
-            loadFromFile(*pkPath, pk);
-        }
-    }
-
-    void saveProvingKey(std::string path) {
-        if (pk) {
-            saveToFile(path, *pk);
-        } else {
-            throw std::runtime_error("cannot save proving key; key doesn't exist");
-        }
-    }
-    void loadVerifyingKey(std::string path) {
-        LOCK(cs_LoadKeys);
-
-        loadFromFile(path, vk);
-
-        processVerifyingKey();
-    }
-    void processVerifyingKey() {
-        vk_precomp = r1cs_ppzksnark_verifier_process_vk(*vk);
-    }
-    void saveVerifyingKey(std::string path) {
-        if (vk) {
-            saveToFile(path, *vk);
-        } else {
-            throw std::runtime_error("cannot save verifying key; key doesn't exist");
-        }
-    }
-    void saveR1CS(std::string path) {
-        auto r1cs = generate_r1cs();
-
-        saveToFile(path, r1cs);
-    }
-
-    r1cs_constraint_system<FieldT> generate_r1cs() {
+    static void generate(const std::string r1csPath,
+                         const std::string vkPath,
+                         const std::string pkPath)
+    {
         protoboard<FieldT> pb;
 
         joinsplit_gadget<FieldT, NumInputs, NumOutputs> g(pb);
         g.generate_r1cs_constraints();
 
-        return pb.get_constraint_system();
-    }
+        auto r1cs = pb.get_constraint_system();
 
-    void generate() {
-        LOCK(cs_LoadKeys);
+        saveToFile(r1csPath, r1cs);
 
-        const r1cs_constraint_system<FieldT> constraint_system = generate_r1cs();
-        r1cs_ppzksnark_keypair<ppzksnark_ppT> keypair = r1cs_ppzksnark_generator<ppzksnark_ppT>(constraint_system);
+        r1cs_ppzksnark_keypair<ppzksnark_ppT> keypair = r1cs_ppzksnark_generator<ppzksnark_ppT>(r1cs);
 
-        pk = keypair.pk;
-        vk = keypair.vk;
-        processVerifyingKey();
+        saveToFile(vkPath, keypair.vk);
+        saveToFile(pkPath, keypair.pk);
     }
 
     bool verify(
@@ -154,10 +110,6 @@ public:
         uint64_t vpub_new,
         const uint256& rt
     ) {
-        if (!vk || !vk_precomp) {
-            throw std::runtime_error("JoinSplit verifying key not loaded");
-        }
-
         try {
             auto r1cs_proof = proof.to_libsnark_proof<r1cs_ppzksnark_proof<ppzksnark_ppT>>();
 
@@ -174,8 +126,8 @@ public:
             );
 
             return verifier.check(
-                *vk,
-                *vk_precomp,
+                vk,
+                vk_precomp,
                 witness,
                 r1cs_proof
             );
@@ -200,10 +152,6 @@ public:
         const uint256& rt,
         bool computeProof
     ) {
-        if (computeProof && !pk) {
-            throw std::runtime_error("JoinSplit proving key not loaded");
-        }
-
         if (vpub_old > MAX_MONEY) {
             throw std::invalid_argument("nonsensical vpub_old value");
         }
@@ -345,8 +293,14 @@ public:
         // estimate that it doesn't matter if we check every time.
         pb.constraint_system.swap_AB_if_beneficial();
 
-        return ZCProof(r1cs_ppzksnark_prover<ppzksnark_ppT>(
-            *pk,
+        std::ifstream fh(pkPath, std::ios::binary);
+
+        if(!fh.is_open()) {
+            throw std::runtime_error(strprintf("could not load param file at %s", pkPath));
+        }
+
+        return ZCProof(r1cs_ppzksnark_prover_streaming<ppzksnark_ppT>(
+            fh,
             primary_input,
             aux_input,
             pb.constraint_system
@@ -355,20 +309,20 @@ public:
 };
 
 template<size_t NumInputs, size_t NumOutputs>
-JoinSplit<NumInputs, NumOutputs>* JoinSplit<NumInputs, NumOutputs>::Generate()
+void JoinSplit<NumInputs, NumOutputs>::Generate(const std::string r1csPath,
+                                                const std::string vkPath,
+                                                const std::string pkPath)
 {
     initialize_curve_params();
-    auto js = new JoinSplitCircuit<NumInputs, NumOutputs>();
-    js->generate();
-
-    return js;
+    JoinSplitCircuit<NumInputs, NumOutputs>::generate(r1csPath, vkPath, pkPath);
 }
 
 template<size_t NumInputs, size_t NumOutputs>
-JoinSplit<NumInputs, NumOutputs>* JoinSplit<NumInputs, NumOutputs>::Unopened()
+JoinSplit<NumInputs, NumOutputs>* JoinSplit<NumInputs, NumOutputs>::Prepared(const std::string vkPath,
+                                                                             const std::string pkPath)
 {
     initialize_curve_params();
-    return new JoinSplitCircuit<NumInputs, NumOutputs>();
+    return new JoinSplitCircuit<NumInputs, NumOutputs>(vkPath, pkPath);
 }
 
 template<size_t NumInputs, size_t NumOutputs>
diff --git a/src/zcash/JoinSplit.hpp b/src/zcash/JoinSplit.hpp
index a8c08d21b..2d9921ac8 100644
--- a/src/zcash/JoinSplit.hpp
+++ b/src/zcash/JoinSplit.hpp
@@ -48,22 +48,17 @@ class JoinSplit {
 public:
     virtual ~JoinSplit() {}
 
-    static JoinSplit<NumInputs, NumOutputs>* Generate();
-    static JoinSplit<NumInputs, NumOutputs>* Unopened();
+    static void Generate(const std::string r1csPath,
+                         const std::string vkPath,
+                         const std::string pkPath);
+    static JoinSplit<NumInputs, NumOutputs>* Prepared(const std::string vkPath,
+                                                      const std::string pkPath);
+
     static uint256 h_sig(const uint256& randomSeed,
                          const boost::array<uint256, NumInputs>& nullifiers,
                          const uint256& pubKeyHash
                         );
 
-    // TODO: #789
-    virtual void setProvingKeyPath(std::string) = 0;
-    virtual void loadProvingKey() = 0;
-
-    virtual void saveProvingKey(std::string path) = 0;
-    virtual void loadVerifyingKey(std::string path) = 0;
-    virtual void saveVerifyingKey(std::string path) = 0;
-    virtual void saveR1CS(std::string path) = 0;
-
     virtual ZCProof prove(
         const boost::array<JSInput, NumInputs>& inputs,
         const boost::array<JSOutput, NumOutputs>& outputs,
diff --git a/src/zcbenchmarks.cpp b/src/zcbenchmarks.cpp
index 1cb880ea1..bb51cdd6c 100644
--- a/src/zcbenchmarks.cpp
+++ b/src/zcbenchmarks.cpp
@@ -97,11 +97,7 @@ double benchmark_parameter_loading()
     struct timeval tv_start;
     timer_start(tv_start);
 
-    auto newParams = ZCJoinSplit::Unopened();
-
-    newParams->loadVerifyingKey(vk_path.string());
-    newParams->setProvingKeyPath(pk_path.string());
-    newParams->loadProvingKey();
+    auto newParams = ZCJoinSplit::Prepared(vk_path.string(), pk_path.string());
 
     double ret = timer_stop(tv_start);