diff --git a/src/test/DoS_tests.cpp b/src/test/DoS_tests.cpp
index 1fbfdaf9b..038579c65 100644
--- a/src/test/DoS_tests.cpp
+++ b/src/test/DoS_tests.cpp
@@ -1,398 +1,398 @@
 // Copyright (c) 2011-2016 The Bitcoin Core developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 // Unit tests for denial-of-service detection/prevention code
 
 #include <chain.h>
 #include <chainparams.h>
 #include <config.h>
 #include <keystore.h>
 #include <net.h>
 #include <net_processing.h>
 #include <pow.h>
 #include <script/sign.h>
 #include <serialize.h>
 #include <util.h>
 #include <validation.h>
 
 #include <test/test_bitcoin.h>
 
 #include <boost/test/unit_test.hpp>
 
 #include <cstdint>
 
 // Tests these internal-to-net_processing.cpp methods:
 extern bool AddOrphanTx(const CTransactionRef &tx, NodeId peer);
 extern void EraseOrphansFor(NodeId peer);
 extern unsigned int LimitOrphanTxSize(unsigned int nMaxOrphans);
 struct COrphanTx {
     CTransactionRef tx;
     NodeId fromPeer;
     int64_t nTimeExpire;
 };
 extern std::map<uint256, COrphanTx> mapOrphanTransactions;
 
 CService ip(uint32_t i) {
     struct in_addr s;
     s.s_addr = i;
     return CService(CNetAddr(s), Params().GetDefaultPort());
 }
 
 static NodeId id = 0;
 
 void UpdateLastBlockAnnounceTime(NodeId node, int64_t time_in_seconds);
 
 BOOST_FIXTURE_TEST_SUITE(DoS_tests, TestingSetup)
 
 // Test eviction of an outbound peer whose chain never advances
 // Mock a node connection, and use mocktime to simulate a peer which never sends
 // any headers messages. PeerLogic should decide to evict that outbound peer,
 // after the appropriate timeouts.
 // Note that we protect 4 outbound nodes from being subject to this logic; this
 // test takes advantage of that protection only being applied to nodes which
 // send headers with sufficient work.
 BOOST_AUTO_TEST_CASE(outbound_slow_chain_eviction) {
     const Config &config = GetConfig();
     std::atomic<bool> interruptDummy(false);
 
     // Mock an outbound peer
     CAddress addr1(ip(0xa0b0c001), NODE_NONE);
     CNode dummyNode1(id++, ServiceFlags(NODE_NETWORK), 0, INVALID_SOCKET, addr1,
                      0, 0, CAddress(), "",
                      /*fInboundIn=*/false);
     dummyNode1.SetSendVersion(PROTOCOL_VERSION);
 
     peerLogic->InitializeNode(config, &dummyNode1);
     dummyNode1.nVersion = 1;
     dummyNode1.fSuccessfullyConnected = true;
 
     // This test requires that we have a chain with non-zero work.
     LOCK(cs_main);
     BOOST_CHECK(chainActive.Tip() != nullptr);
     BOOST_CHECK(chainActive.Tip()->nChainWork > 0);
 
     // Test starts here
     LOCK(dummyNode1.cs_sendProcessing);
     // should result in getheaders
     peerLogic->SendMessages(config, &dummyNode1, interruptDummy);
     LOCK(dummyNode1.cs_vSend);
     BOOST_CHECK(dummyNode1.vSendMsg.size() > 0);
     dummyNode1.vSendMsg.clear();
 
     int64_t nStartTime = GetTime();
     // Wait 21 minutes
     SetMockTime(nStartTime + 21 * 60);
     // should result in getheaders
     peerLogic->SendMessages(config, &dummyNode1, interruptDummy);
     BOOST_CHECK(dummyNode1.vSendMsg.size() > 0);
     // Wait 3 more minutes
     SetMockTime(nStartTime + 24 * 60);
     // should result in disconnect
     peerLogic->SendMessages(config, &dummyNode1, interruptDummy);
     BOOST_CHECK(dummyNode1.fDisconnect == true);
     SetMockTime(0);
 
     bool dummy;
     peerLogic->FinalizeNode(config, dummyNode1.GetId(), dummy);
 }
 
-void AddRandomOutboundPeer(const Config &config,
-                           std::vector<std::unique_ptr<CNode>> &vNodes,
-                           PeerLogicValidation &peerLogic) {
-    CAddress addr(ip(GetRandInt(0xffffffff)), NODE_NONE);
+static void AddRandomOutboundPeer(const Config &config,
+                                  std::vector<std::unique_ptr<CNode>> &vNodes,
+                                  PeerLogicValidation &peerLogic) {
+    CAddress addr(ip(insecure_rand_ctx.randbits(32)), NODE_NONE);
     vNodes.emplace_back(new CNode(id++, ServiceFlags(NODE_NETWORK), 0,
                                   INVALID_SOCKET, addr, 0, 0, CAddress(), "",
                                   /*fInboundIn=*/false));
     CNode &node = *vNodes.back();
     node.SetSendVersion(PROTOCOL_VERSION);
 
     peerLogic.InitializeNode(config, &node);
     node.nVersion = 1;
     node.fSuccessfullyConnected = true;
 
     CConnmanTest::AddNode(node);
 }
 
 BOOST_AUTO_TEST_CASE(stale_tip_peer_management) {
     const Config &config = GetConfig();
     const Consensus::Params &consensusParams =
         config.GetChainParams().GetConsensus();
     constexpr int nMaxOutbound = 8;
     CConnman::Options options;
     options.nMaxConnections = 125;
     options.nMaxOutbound = nMaxOutbound;
     options.nMaxFeeler = 1;
 
     connman->Init(options);
     std::vector<std::unique_ptr<CNode>> vNodes;
 
     // Mock some outbound peers
     for (int i = 0; i < nMaxOutbound; ++i) {
         AddRandomOutboundPeer(config, vNodes, *peerLogic);
     }
 
     peerLogic->CheckForStaleTipAndEvictPeers(consensusParams);
 
     // No nodes should be marked for disconnection while we have no extra peers
     for (auto const &node : vNodes) {
         BOOST_CHECK(node->fDisconnect == false);
     }
 
     SetMockTime(GetTime() + 3 * consensusParams.nPowTargetSpacing + 1);
 
     // Now tip should definitely be stale, and we should look for an extra
     // outbound peer
     peerLogic->CheckForStaleTipAndEvictPeers(consensusParams);
     BOOST_CHECK(connman->GetTryNewOutboundPeer());
 
     // Still no peers should be marked for disconnection
     for (auto const &node : vNodes) {
         BOOST_CHECK(node->fDisconnect == false);
     }
 
     // If we add one more peer, something should get marked for eviction
     // on the next check (since we're mocking the time to be in the future, the
     // required time connected check should be satisfied).
     AddRandomOutboundPeer(config, vNodes, *peerLogic);
 
     peerLogic->CheckForStaleTipAndEvictPeers(consensusParams);
     for (int i = 0; i < nMaxOutbound; ++i) {
         BOOST_CHECK(vNodes[i]->fDisconnect == false);
     }
     // Last added node should get marked for eviction
     BOOST_CHECK(vNodes.back()->fDisconnect == true);
 
     vNodes.back()->fDisconnect = false;
 
     // Update the last announced block time for the last
     // peer, and check that the next newest node gets evicted.
     UpdateLastBlockAnnounceTime(vNodes.back()->GetId(), GetTime());
 
     peerLogic->CheckForStaleTipAndEvictPeers(consensusParams);
     for (int i = 0; i < nMaxOutbound - 1; ++i) {
         BOOST_CHECK(vNodes[i]->fDisconnect == false);
     }
     BOOST_CHECK(vNodes[nMaxOutbound - 1]->fDisconnect == true);
     BOOST_CHECK(vNodes.back()->fDisconnect == false);
 
     bool dummy;
     for (auto const &node : vNodes) {
         peerLogic->FinalizeNode(config, node->GetId(), dummy);
     }
 
     CConnmanTest::ClearNodes();
 }
 
 BOOST_AUTO_TEST_CASE(DoS_banning) {
     const Config &config = GetConfig();
     std::atomic<bool> interruptDummy(false);
 
     connman->ClearBanned();
     CAddress addr1(ip(0xa0b0c001), NODE_NONE);
     CNode dummyNode1(id++, NODE_NETWORK, 0, INVALID_SOCKET, addr1, 0, 0,
                      CAddress(), "", true);
     dummyNode1.SetSendVersion(PROTOCOL_VERSION);
     peerLogic->InitializeNode(config, &dummyNode1);
     dummyNode1.nVersion = 1;
     dummyNode1.fSuccessfullyConnected = true;
     {
         LOCK(cs_main);
         // Should get banned.
         Misbehaving(dummyNode1.GetId(), 100, "");
     }
     LOCK(dummyNode1.cs_sendProcessing);
     peerLogic->SendMessages(config, &dummyNode1, interruptDummy);
     BOOST_CHECK(connman->IsBanned(addr1));
     // Different IP, not banned.
     BOOST_CHECK(!connman->IsBanned(ip(0xa0b0c001 | 0x0000ff00)));
 
     CAddress addr2(ip(0xa0b0c002), NODE_NONE);
     CNode dummyNode2(id++, NODE_NETWORK, 0, INVALID_SOCKET, addr2, 1, 1,
                      CAddress(), "", true);
     dummyNode2.SetSendVersion(PROTOCOL_VERSION);
     peerLogic->InitializeNode(config, &dummyNode2);
     dummyNode2.nVersion = 1;
     dummyNode2.fSuccessfullyConnected = true;
     {
         LOCK(cs_main);
         Misbehaving(dummyNode2.GetId(), 50, "");
     }
     LOCK(dummyNode2.cs_sendProcessing);
     peerLogic->SendMessages(config, &dummyNode2, interruptDummy);
     // 2 not banned yet...
     BOOST_CHECK(!connman->IsBanned(addr2));
     // ... but 1 still should be.
     BOOST_CHECK(connman->IsBanned(addr1));
     {
         LOCK(cs_main);
         Misbehaving(dummyNode2.GetId(), 50, "");
     }
     peerLogic->SendMessages(config, &dummyNode2, interruptDummy);
     BOOST_CHECK(connman->IsBanned(addr2));
 
     bool dummy;
     peerLogic->FinalizeNode(config, dummyNode1.GetId(), dummy);
     peerLogic->FinalizeNode(config, dummyNode2.GetId(), dummy);
 }
 
 BOOST_AUTO_TEST_CASE(DoS_banscore) {
     const Config &config = GetConfig();
     std::atomic<bool> interruptDummy(false);
 
     connman->ClearBanned();
     // because 11 is my favorite number.
     gArgs.ForceSetArg("-banscore", "111");
     CAddress addr1(ip(0xa0b0c001), NODE_NONE);
     CNode dummyNode1(id++, NODE_NETWORK, 0, INVALID_SOCKET, addr1, 3, 1,
                      CAddress(), "", true);
     dummyNode1.SetSendVersion(PROTOCOL_VERSION);
     peerLogic->InitializeNode(config, &dummyNode1);
     dummyNode1.nVersion = 1;
     dummyNode1.fSuccessfullyConnected = true;
     {
         LOCK(cs_main);
         Misbehaving(dummyNode1.GetId(), 100, "");
     }
     LOCK(dummyNode1.cs_sendProcessing);
     peerLogic->SendMessages(config, &dummyNode1, interruptDummy);
     BOOST_CHECK(!connman->IsBanned(addr1));
     {
         LOCK(cs_main);
         Misbehaving(dummyNode1.GetId(), 10, "");
     }
     peerLogic->SendMessages(config, &dummyNode1, interruptDummy);
     BOOST_CHECK(!connman->IsBanned(addr1));
     {
         LOCK(cs_main);
         Misbehaving(dummyNode1.GetId(), 1, "");
     }
     peerLogic->SendMessages(config, &dummyNode1, interruptDummy);
     BOOST_CHECK(connman->IsBanned(addr1));
     gArgs.ForceSetArg("-banscore", std::to_string(DEFAULT_BANSCORE_THRESHOLD));
 
     bool dummy;
     peerLogic->FinalizeNode(config, dummyNode1.GetId(), dummy);
 }
 
 BOOST_AUTO_TEST_CASE(DoS_bantime) {
     const Config &config = GetConfig();
     std::atomic<bool> interruptDummy(false);
 
     connman->ClearBanned();
     int64_t nStartTime = GetTime();
     // Overrides future calls to GetTime()
     SetMockTime(nStartTime);
 
     CAddress addr(ip(0xa0b0c001), NODE_NONE);
     CNode dummyNode(id++, NODE_NETWORK, 0, INVALID_SOCKET, addr, 4, 4,
                     CAddress(), "", true);
     dummyNode.SetSendVersion(PROTOCOL_VERSION);
     peerLogic->InitializeNode(config, &dummyNode);
     dummyNode.nVersion = 1;
     dummyNode.fSuccessfullyConnected = true;
 
     {
         LOCK(cs_main);
         Misbehaving(dummyNode.GetId(), 100, "");
     }
     LOCK(dummyNode.cs_sendProcessing);
     peerLogic->SendMessages(config, &dummyNode, interruptDummy);
     BOOST_CHECK(connman->IsBanned(addr));
 
     SetMockTime(nStartTime + 60 * 60);
     BOOST_CHECK(connman->IsBanned(addr));
 
     SetMockTime(nStartTime + 60 * 60 * 24 + 1);
     BOOST_CHECK(!connman->IsBanned(addr));
 
     bool dummy;
     peerLogic->FinalizeNode(config, dummyNode.GetId(), dummy);
 }
 
 CTransactionRef RandomOrphan() {
     std::map<uint256, COrphanTx>::iterator it;
     LOCK(cs_main);
     it = mapOrphanTransactions.lower_bound(InsecureRand256());
     if (it == mapOrphanTransactions.end()) {
         it = mapOrphanTransactions.begin();
     }
     return it->second.tx;
 }
 
 BOOST_AUTO_TEST_CASE(DoS_mapOrphans) {
     CKey key;
     key.MakeNewKey(true);
     CBasicKeyStore keystore;
     keystore.AddKey(key);
 
     // 50 orphan transactions:
     for (int i = 0; i < 50; i++) {
         CMutableTransaction tx;
         tx.vin.resize(1);
         tx.vin[0].prevout = COutPoint(InsecureRand256(), 0);
         tx.vin[0].scriptSig << OP_1;
         tx.vout.resize(1);
         tx.vout[0].nValue = 1 * CENT;
         tx.vout[0].scriptPubKey =
             GetScriptForDestination(key.GetPubKey().GetID());
 
         AddOrphanTx(MakeTransactionRef(tx), i);
     }
 
     // ... and 50 that depend on other orphans:
     for (int i = 0; i < 50; i++) {
         CTransactionRef txPrev = RandomOrphan();
 
         CMutableTransaction tx;
         tx.vin.resize(1);
         tx.vin[0].prevout = COutPoint(txPrev->GetId(), 0);
         tx.vout.resize(1);
         tx.vout[0].nValue = 1 * CENT;
         tx.vout[0].scriptPubKey =
             GetScriptForDestination(key.GetPubKey().GetID());
         SignSignature(keystore, *txPrev, tx, 0, SigHashType());
 
         AddOrphanTx(MakeTransactionRef(tx), i);
     }
 
     // This really-big orphan should be ignored:
     for (int i = 0; i < 10; i++) {
         CTransactionRef txPrev = RandomOrphan();
 
         CMutableTransaction tx;
         tx.vout.resize(1);
         tx.vout[0].nValue = 1 * CENT;
         tx.vout[0].scriptPubKey =
             GetScriptForDestination(key.GetPubKey().GetID());
         tx.vin.resize(2777);
         for (size_t j = 0; j < tx.vin.size(); j++) {
             tx.vin[j].prevout = COutPoint(txPrev->GetId(), j);
         }
         SignSignature(keystore, *txPrev, tx, 0, SigHashType());
         // Re-use same signature for other inputs
         // (they don't have to be valid for this test)
         for (unsigned int j = 1; j < tx.vin.size(); j++)
             tx.vin[j].scriptSig = tx.vin[0].scriptSig;
 
         BOOST_CHECK(!AddOrphanTx(MakeTransactionRef(tx), i));
     }
 
     LOCK(cs_main);
     // Test EraseOrphansFor:
     for (NodeId i = 0; i < 3; i++) {
         size_t sizeBefore = mapOrphanTransactions.size();
         EraseOrphansFor(i);
         BOOST_CHECK(mapOrphanTransactions.size() < sizeBefore);
     }
 
     // Test LimitOrphanTxSize() function:
     LimitOrphanTxSize(40);
     BOOST_CHECK(mapOrphanTransactions.size() <= 40);
     LimitOrphanTxSize(10);
     BOOST_CHECK(mapOrphanTransactions.size() <= 10);
     LimitOrphanTxSize(0);
     BOOST_CHECK(mapOrphanTransactions.empty());
 }
 
 BOOST_AUTO_TEST_SUITE_END()
diff --git a/src/test/cuckoocache_tests.cpp b/src/test/cuckoocache_tests.cpp
index dc6a4dffc..1a2a23034 100644
--- a/src/test/cuckoocache_tests.cpp
+++ b/src/test/cuckoocache_tests.cpp
@@ -1,399 +1,384 @@
 // Copyright (c) 2012-2016 The Bitcoin Core developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #include <cuckoocache.h>
 
 #include <random.h>
 #include <script/sigcache.h>
 
 #include <test/test_bitcoin.h>
 
 #include <boost/test/unit_test.hpp>
 #include <boost/thread/shared_mutex.hpp>
 
 /** Test Suite for CuckooCache
  *
  *  1) All tests should have a deterministic result (using insecure rand
  *  with deterministic seeds)
  *  2) Some test methods are templated to allow for easier testing
  *  against new versions / comparing
  *  3) Results should be treated as a regression test, i.e., did the behavior
  *  change significantly from what was expected. This can be OK, depending on
  *  the nature of the change, but requires updating the tests to reflect the new
  *  expected behavior. For example improving the hit rate may cause some tests
  *  using BOOST_CHECK_CLOSE to fail.
  */
-FastRandomContext local_rand_ctx(true);
-
 BOOST_AUTO_TEST_SUITE(cuckoocache_tests);
 
-/**
- * insecure_GetRandHash fills in a uint256 from local_rand_ctx
- */
-void insecure_GetRandHash(uint256 &t) {
-    uint32_t *ptr = (uint32_t *)t.begin();
-    for (uint8_t j = 0; j < 8; ++j) {
-        *(ptr++) = local_rand_ctx.rand32();
-    }
-}
-
 /**
  * Test that no values not inserted into the cache are read out of it.
  *
  * There are no repeats in the first 200000 insecure_GetRandHash calls
  */
 BOOST_AUTO_TEST_CASE(test_cuckoocache_no_fakes) {
-    local_rand_ctx = FastRandomContext(true);
+    SeedInsecureRand(true);
     CuckooCache::cache<uint256, SignatureCacheHasher> cc{};
     size_t megabytes = 4;
     cc.setup_bytes(megabytes << 20);
-    uint256 v;
     for (int x = 0; x < 100000; ++x) {
-        insecure_GetRandHash(v);
-        cc.insert(v);
+        cc.insert(InsecureRand256());
     }
     for (int x = 0; x < 100000; ++x) {
-        insecure_GetRandHash(v);
-        BOOST_CHECK(!cc.contains(v, false));
+        BOOST_CHECK(!cc.contains(InsecureRand256(), false));
     }
 };
 
 /**
  * This helper returns the hit rate when megabytes*load worth of entries are
  * inserted into a megabytes sized cache
  */
 template <typename Cache> double test_cache(size_t megabytes, double load) {
-    local_rand_ctx = FastRandomContext(true);
+    SeedInsecureRand(true);
     std::vector<uint256> hashes;
     Cache set{};
     size_t bytes = megabytes * (1 << 20);
     set.setup_bytes(bytes);
     uint32_t n_insert = static_cast<uint32_t>(load * (bytes / sizeof(uint256)));
     hashes.resize(n_insert);
     for (uint32_t i = 0; i < n_insert; ++i) {
         uint32_t *ptr = (uint32_t *)hashes[i].begin();
         for (uint8_t j = 0; j < 8; ++j) {
-            *(ptr++) = local_rand_ctx.rand32();
+            *(ptr++) = InsecureRand32();
         }
     }
     /**
      * We make a copy of the hashes because future optimizations of the
      * cuckoocache may overwrite the inserted element, so the test is "future
      * proofed".
      */
     std::vector<uint256> hashes_insert_copy = hashes;
     /** Do the insert */
     for (uint256 &h : hashes_insert_copy) {
         set.insert(h);
     }
     /** Count the hits */
     uint32_t count = 0;
     for (uint256 &h : hashes) {
         count += set.contains(h, false);
     }
     double hit_rate = double(count) / double(n_insert);
     return hit_rate;
 }
 
 /** The normalized hit rate for a given load.
  *
  * The semantics are a little confusing, so please see the below
  * explanation.
  *
  * Examples:
  *
  * 1) at load 0.5, we expect a perfect hit rate, so we multiply by
  * 1.0
  * 2) at load 2.0, we expect to see half the entries, so a perfect hit rate
  * would be 0.5. Therefore, if we see a hit rate of 0.4, 0.4*2.0 = 0.8 is the
  * normalized hit rate.
  *
  * This is basically the right semantics, but has a bit of a glitch depending on
  * how you measure around load 1.0 as after load 1.0 your normalized hit rate
  * becomes effectively perfect, ignoring freshness.
  */
 double normalize_hit_rate(double hits, double load) {
     return hits * std::max(load, 1.0);
 }
 
 /** Check the hit rate on loads ranging from 0.1 to 2.0 */
 BOOST_AUTO_TEST_CASE(cuckoocache_hit_rate_ok) {
     /**
      * Arbitrarily selected Hit Rate threshold that happens to work for this
      * test as a lower bound on performance.
      */
     double HitRateThresh = 0.98;
     size_t megabytes = 4;
     for (double load = 0.1; load < 2; load *= 2) {
         double hits =
             test_cache<CuckooCache::cache<uint256, SignatureCacheHasher>>(
                 megabytes, load);
         BOOST_CHECK(normalize_hit_rate(hits, load) > HitRateThresh);
     }
 }
 
 /** This helper checks that erased elements are preferentially inserted onto and
  * that the hit rate of "fresher" keys is reasonable*/
 template <typename Cache> void test_cache_erase(size_t megabytes) {
     double load = 1;
-    local_rand_ctx = FastRandomContext(true);
+    SeedInsecureRand(true);
     std::vector<uint256> hashes;
     Cache set{};
     size_t bytes = megabytes * (1 << 20);
     set.setup_bytes(bytes);
     uint32_t n_insert = static_cast<uint32_t>(load * (bytes / sizeof(uint256)));
     hashes.resize(n_insert);
     for (uint32_t i = 0; i < n_insert; ++i) {
         uint32_t *ptr = (uint32_t *)hashes[i].begin();
         for (uint8_t j = 0; j < 8; ++j) {
-            *(ptr++) = local_rand_ctx.rand32();
+            *(ptr++) = InsecureRand32();
         }
     }
     /** We make a copy of the hashes because future optimizations of the
      * cuckoocache may overwrite the inserted element, so the test is
      * "future proofed".
      */
     std::vector<uint256> hashes_insert_copy = hashes;
 
     /** Insert the first half */
     for (uint32_t i = 0; i < (n_insert / 2); ++i) {
         set.insert(hashes_insert_copy[i]);
     }
     /** Erase the first quarter */
     for (uint32_t i = 0; i < (n_insert / 4); ++i) {
         set.contains(hashes[i], true);
     }
     /** Insert the second half */
     for (uint32_t i = (n_insert / 2); i < n_insert; ++i) {
         set.insert(hashes_insert_copy[i]);
     }
 
     /** elements that we marked erased but that are still there */
     size_t count_erased_but_contained = 0;
     /** elements that we did not erase but are older */
     size_t count_stale = 0;
     /** elements that were most recently inserted */
     size_t count_fresh = 0;
 
     for (uint32_t i = 0; i < (n_insert / 4); ++i) {
         count_erased_but_contained += set.contains(hashes[i], false);
     }
     for (uint32_t i = (n_insert / 4); i < (n_insert / 2); ++i) {
         count_stale += set.contains(hashes[i], false);
     }
     for (uint32_t i = (n_insert / 2); i < n_insert; ++i) {
         count_fresh += set.contains(hashes[i], false);
     }
 
     double hit_rate_erased_but_contained =
         double(count_erased_but_contained) / (double(n_insert) / 4.0);
     double hit_rate_stale = double(count_stale) / (double(n_insert) / 4.0);
     double hit_rate_fresh = double(count_fresh) / (double(n_insert) / 2.0);
 
     // Check that our hit_rate_fresh is perfect
     BOOST_CHECK_EQUAL(hit_rate_fresh, 1.0);
     // Check that we have a more than 2x better hit rate on stale elements than
     // erased elements.
     BOOST_CHECK(hit_rate_stale > 2 * hit_rate_erased_but_contained);
 }
 
 BOOST_AUTO_TEST_CASE(cuckoocache_erase_ok) {
     size_t megabytes = 4;
     test_cache_erase<CuckooCache::cache<uint256, SignatureCacheHasher>>(
         megabytes);
 }
 
 template <typename Cache> void test_cache_erase_parallel(size_t megabytes) {
     double load = 1;
-    local_rand_ctx = FastRandomContext(true);
+    SeedInsecureRand(true);
     std::vector<uint256> hashes;
     Cache set{};
     size_t bytes = megabytes * (1 << 20);
     set.setup_bytes(bytes);
     uint32_t n_insert = static_cast<uint32_t>(load * (bytes / sizeof(uint256)));
     hashes.resize(n_insert);
     for (uint32_t i = 0; i < n_insert; ++i) {
         uint32_t *ptr = (uint32_t *)hashes[i].begin();
         for (uint8_t j = 0; j < 8; ++j) {
-            *(ptr++) = local_rand_ctx.rand32();
+            *(ptr++) = InsecureRand32();
         }
     }
     /** We make a copy of the hashes because future optimizations of the
      * cuckoocache may overwrite the inserted element, so the test is
      * "future proofed".
      */
     std::vector<uint256> hashes_insert_copy = hashes;
     boost::shared_mutex mtx;
 
     {
         /** Grab lock to make sure we release inserts */
         boost::unique_lock<boost::shared_mutex> l(mtx);
         /** Insert the first half */
         for (uint32_t i = 0; i < (n_insert / 2); ++i) {
             set.insert(hashes_insert_copy[i]);
         }
     }
 
     /** Spin up 3 threads to run contains with erase.
      */
     std::vector<std::thread> threads;
     /** Erase the first quarter */
     for (uint32_t x = 0; x < 3; ++x)
         /** Each thread is emplaced with x copy-by-value */
         threads.emplace_back([&, x] {
             boost::shared_lock<boost::shared_mutex> l(mtx);
             size_t ntodo = (n_insert / 4) / 3;
             size_t start = ntodo * x;
             size_t end = ntodo * (x + 1);
             for (uint32_t i = start; i < end; ++i) {
                 set.contains(hashes[i], true);
             }
         });
 
     /** Wait for all threads to finish */
     for (std::thread &t : threads) {
         t.join();
     }
     /** Grab lock to make sure we observe erases */
     boost::unique_lock<boost::shared_mutex> l(mtx);
     /** Insert the second half */
     for (uint32_t i = (n_insert / 2); i < n_insert; ++i) {
         set.insert(hashes_insert_copy[i]);
     }
 
     /** elements that we marked erased but that are still there */
     size_t count_erased_but_contained = 0;
     /** elements that we did not erase but are older */
     size_t count_stale = 0;
     /** elements that were most recently inserted */
     size_t count_fresh = 0;
 
     for (uint32_t i = 0; i < (n_insert / 4); ++i) {
         count_erased_but_contained += set.contains(hashes[i], false);
     }
     for (uint32_t i = (n_insert / 4); i < (n_insert / 2); ++i) {
         count_stale += set.contains(hashes[i], false);
     }
     for (uint32_t i = (n_insert / 2); i < n_insert; ++i) {
         count_fresh += set.contains(hashes[i], false);
     }
 
     double hit_rate_erased_but_contained =
         double(count_erased_but_contained) / (double(n_insert) / 4.0);
     double hit_rate_stale = double(count_stale) / (double(n_insert) / 4.0);
     double hit_rate_fresh = double(count_fresh) / (double(n_insert) / 2.0);
 
     // Check that our hit_rate_fresh is perfect
     BOOST_CHECK_EQUAL(hit_rate_fresh, 1.0);
     // Check that we have a more than 2x better hit rate on stale elements than
     // erased elements.
     BOOST_CHECK(hit_rate_stale > 2 * hit_rate_erased_but_contained);
 }
 
 BOOST_AUTO_TEST_CASE(cuckoocache_erase_parallel_ok) {
     size_t megabytes = 4;
     test_cache_erase_parallel<
         CuckooCache::cache<uint256, SignatureCacheHasher>>(megabytes);
 }
 
 template <typename Cache> void test_cache_generations() {
     // This test checks that for a simulation of network activity, the fresh hit
     // rate is never below 99%, and the number of times that it is worse than
     // 99.9% are less than 1% of the time.
     double min_hit_rate = 0.99;
     double tight_hit_rate = 0.999;
     double max_rate_less_than_tight_hit_rate = 0.01;
     // A cache that meets this specification is therefore shown to have a hit
     // rate of at least tight_hit_rate * (1 - max_rate_less_than_tight_hit_rate)
     // +
     // min_hit_rate*max_rate_less_than_tight_hit_rate = 0.999*99%+0.99*1% ==
     // 99.89%
     // hit rate with low variance.
 
     // We use deterministic values, but this test has also passed on many
     // iterations with non-deterministic values, so it isn't "overfit" to the
     // specific entropy in FastRandomContext(true) and implementation of the
     // cache.
-    local_rand_ctx = FastRandomContext(true);
+    SeedInsecureRand(true);
 
     // block_activity models a chunk of network activity. n_insert elements are
     // adde to the cache. The first and last n/4 are stored for removal later
     // and the middle n/2 are not stored. This models a network which uses half
     // the signatures of recently (since the last block) added transactions
     // immediately and never uses the other half.
     struct block_activity {
         std::vector<uint256> reads;
         block_activity(uint32_t n_insert, Cache &c) : reads() {
             std::vector<uint256> inserts;
             inserts.resize(n_insert);
             reads.reserve(n_insert / 2);
             for (uint32_t i = 0; i < n_insert; ++i) {
                 uint32_t *ptr = (uint32_t *)inserts[i].begin();
                 for (uint8_t j = 0; j < 8; ++j) {
-                    *(ptr++) = local_rand_ctx.rand32();
+                    *(ptr++) = InsecureRand32();
                 }
             }
             for (uint32_t i = 0; i < n_insert / 4; ++i) {
                 reads.push_back(inserts[i]);
             }
             for (uint32_t i = n_insert - (n_insert / 4); i < n_insert; ++i) {
                 reads.push_back(inserts[i]);
             }
             for (auto h : inserts) {
                 c.insert(h);
             }
         }
     };
 
     const uint32_t BLOCK_SIZE = 1000;
     // We expect window size 60 to perform reasonably given that each epoch
     // stores 45% of the cache size (~472k).
     const uint32_t WINDOW_SIZE = 60;
     const uint32_t POP_AMOUNT = (BLOCK_SIZE / WINDOW_SIZE) / 2;
     const double load = 10;
     const size_t megabytes = 4;
     const size_t bytes = megabytes * (1 << 20);
     const uint32_t n_insert =
         static_cast<uint32_t>(load * (bytes / sizeof(uint256)));
 
     std::vector<block_activity> hashes;
     Cache set{};
     set.setup_bytes(bytes);
     hashes.reserve(n_insert / BLOCK_SIZE);
     std::deque<block_activity> last_few;
     uint32_t out_of_tight_tolerance = 0;
     uint32_t total = n_insert / BLOCK_SIZE;
     // we use the deque last_few to model a sliding window of blocks. at each
     // step, each of the last WINDOW_SIZE block_activities checks the cache for
     // POP_AMOUNT of the hashes that they inserted, and marks these erased.
     for (uint32_t i = 0; i < total; ++i) {
         if (last_few.size() == WINDOW_SIZE) last_few.pop_front();
         last_few.emplace_back(BLOCK_SIZE, set);
         uint32_t count = 0;
         for (auto &act : last_few) {
             for (uint32_t k = 0; k < POP_AMOUNT; ++k) {
                 count += set.contains(act.reads.back(), true);
                 act.reads.pop_back();
             }
         }
         // We use last_few.size() rather than WINDOW_SIZE for the correct
         // behavior on the first WINDOW_SIZE iterations where the deque is not
         // full yet.
         double hit = double(count) / (last_few.size() * POP_AMOUNT);
         // Loose Check that hit rate is above min_hit_rate
         BOOST_CHECK(hit > min_hit_rate);
         // Tighter check, count number of times we are less than tight_hit_rate
         // (and implicitly, greater than min_hit_rate)
         out_of_tight_tolerance += hit < tight_hit_rate;
     }
     // Check that being out of tolerance happens less than
     // max_rate_less_than_tight_hit_rate of the time
     BOOST_CHECK(double(out_of_tight_tolerance) / double(total) <
                 max_rate_less_than_tight_hit_rate);
 }
 BOOST_AUTO_TEST_CASE(cuckoocache_generations) {
     test_cache_generations<CuckooCache::cache<uint256, SignatureCacheHasher>>();
 }
 
 BOOST_AUTO_TEST_SUITE_END();
diff --git a/src/test/validation_block_tests.cpp b/src/test/validation_block_tests.cpp
index f052e021c..609061981 100644
--- a/src/test/validation_block_tests.cpp
+++ b/src/test/validation_block_tests.cpp
@@ -1,203 +1,203 @@
 // Copyright (c) 2018 The Bitcoin Core developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #include <boost/test/unit_test.hpp>
 
 #include <chain.h>
 #include <chainparams.h>
 #include <config.h>
 #include <consensus/merkle.h>
 #include <consensus/validation.h>
 #include <miner.h>
 #include <pow.h>
 #include <random.h>
 #include <test/test_bitcoin.h>
 #include <utiltime.h>
 #include <validation.h>
 #include <validationinterface.h>
 
 struct RegtestingSetup : public TestingSetup {
     RegtestingSetup() : TestingSetup(CBaseChainParams::REGTEST) {}
 };
 
 BOOST_FIXTURE_TEST_SUITE(validation_block_tests, RegtestingSetup)
 
 struct TestSubscriber : public CValidationInterface {
     uint256 m_expected_tip;
 
     TestSubscriber(uint256 tip) : m_expected_tip(tip) {}
 
     void UpdatedBlockTip(const CBlockIndex *pindexNew,
                          const CBlockIndex *pindexFork, bool fInitialDownload) {
         BOOST_CHECK_EQUAL(m_expected_tip, pindexNew->GetBlockHash());
     }
 
     void BlockConnected(const std::shared_ptr<const CBlock> &block,
                         const CBlockIndex *pindex,
                         const std::vector<CTransactionRef> &txnConflicted) {
         BOOST_CHECK_EQUAL(m_expected_tip, block->hashPrevBlock);
         BOOST_CHECK_EQUAL(m_expected_tip, pindex->pprev->GetBlockHash());
 
         m_expected_tip = block->GetHash();
     }
 
     void BlockDisconnected(const std::shared_ptr<const CBlock> &block) {
         BOOST_CHECK_EQUAL(m_expected_tip, block->GetHash());
 
         m_expected_tip = block->hashPrevBlock;
     }
 };
 
 std::shared_ptr<CBlock> Block(const Config &config, const uint256 &prev_hash) {
     static int i = 0;
     static uint64_t time = config.GetChainParams().GenesisBlock().nTime;
 
     CScript pubKey;
     pubKey << i++ << OP_TRUE;
 
     auto ptemplate = BlockAssembler(config, g_mempool).CreateNewBlock(pubKey);
     auto pblock = std::make_shared<CBlock>(ptemplate->block);
     pblock->hashPrevBlock = prev_hash;
     pblock->nTime = ++time;
 
     CMutableTransaction txCoinbase(*pblock->vtx[0]);
     txCoinbase.vout.resize(1);
     pblock->vtx[0] = MakeTransactionRef(std::move(txCoinbase));
 
     return pblock;
 }
 
 std::shared_ptr<CBlock> FinalizeBlock(const Config &config,
                                       std::shared_ptr<CBlock> pblock) {
     pblock->hashMerkleRoot = BlockMerkleRoot(*pblock);
 
     while (!CheckProofOfWork(pblock->GetHash(), pblock->nBits, config)) {
         ++(pblock->nNonce);
     }
 
     return pblock;
 }
 
 // construct a valid block
 const std::shared_ptr<const CBlock> GoodBlock(const Config &config,
                                               const uint256 &prev_hash) {
     return FinalizeBlock(config, Block(config, prev_hash));
 }
 
 // construct an invalid block (but with a valid header)
 const std::shared_ptr<const CBlock> BadBlock(const Config &config,
                                              const uint256 &prev_hash) {
     auto pblock = Block(config, prev_hash);
 
     CMutableTransaction coinbase_spend;
     coinbase_spend.vin.push_back(
         CTxIn(COutPoint(pblock->vtx[0]->GetHash(), 0), CScript(), 0));
     coinbase_spend.vout.push_back(pblock->vtx[0]->vout[0]);
 
     CTransactionRef tx = MakeTransactionRef(coinbase_spend);
     pblock->vtx.push_back(tx);
 
     auto ret = FinalizeBlock(config, pblock);
     return ret;
 }
 
 void BuildChain(const Config &config, const uint256 &root, int height,
                 const unsigned int invalid_rate, const unsigned int branch_rate,
                 const unsigned int max_size,
                 std::vector<std::shared_ptr<const CBlock>> &blocks) {
     if (height <= 0 || blocks.size() >= max_size) {
         return;
     }
 
-    bool gen_invalid = GetRand(100) < invalid_rate;
-    bool gen_fork = GetRand(100) < branch_rate;
+    bool gen_invalid = InsecureRandRange(100) < invalid_rate;
+    bool gen_fork = InsecureRandRange(100) < branch_rate;
 
     const std::shared_ptr<const CBlock> pblock =
         gen_invalid ? BadBlock(config, root) : GoodBlock(config, root);
     blocks.push_back(pblock);
     if (!gen_invalid) {
         BuildChain(config, pblock->GetHash(), height - 1, invalid_rate,
                    branch_rate, max_size, blocks);
     }
 
     if (gen_fork) {
         blocks.push_back(GoodBlock(config, root));
         BuildChain(config, blocks.back()->GetHash(), height - 1, invalid_rate,
                    branch_rate, max_size, blocks);
     }
 }
 
 BOOST_AUTO_TEST_CASE(processnewblock_signals_ordering) {
     GlobalConfig config;
     const CChainParams &chainParams = config.GetChainParams();
 
     // build a large-ish chain that's likely to have some forks
     std::vector<std::shared_ptr<const CBlock>> blocks;
     while (blocks.size() < 50) {
         blocks.clear();
         BuildChain(config, chainParams.GenesisBlock().GetHash(), 100, 15, 10,
                    500, blocks);
     }
 
     bool ignored;
     CValidationState state;
     std::vector<CBlockHeader> headers;
     std::transform(
         blocks.begin(), blocks.end(), std::back_inserter(headers),
         [](std::shared_ptr<const CBlock> b) { return b->GetBlockHeader(); });
 
     // Process all the headers so we understand the toplogy of the chain
     BOOST_CHECK(ProcessNewBlockHeaders(config, headers, state));
 
     // Connect the genesis block and drain any outstanding events
     ProcessNewBlock(config,
                     std::make_shared<CBlock>(chainParams.GenesisBlock()), true,
                     &ignored);
     SyncWithValidationInterfaceQueue();
 
     // subscribe to events (this subscriber will validate event ordering)
     const CBlockIndex *initial_tip = nullptr;
     {
         LOCK(cs_main);
         initial_tip = chainActive.Tip();
     }
     TestSubscriber sub(initial_tip->GetBlockHash());
     RegisterValidationInterface(&sub);
 
     // create a bunch of threads that repeatedly process a block generated above
     // at random this will create parallelism and randomness inside validation -
     // the ValidationInterface will subscribe to events generated during block
     // validation and assert on ordering invariance
     boost::thread_group threads;
     for (int i = 0; i < 10; i++) {
         threads.create_thread([&config, &blocks]() {
             bool tlignored;
             for (int j = 0; j < 1000; j++) {
-                auto block = blocks[GetRand(blocks.size() - 1)];
+                auto block = blocks[InsecureRandRange(blocks.size() - 1)];
                 ProcessNewBlock(config, block, true, &tlignored);
             }
 
             // to make sure that eventually we process the full chain - do it
             // here
             for (auto block : blocks) {
                 if (block->vtx.size() == 1) {
                     bool processed =
                         ProcessNewBlock(config, block, true, &tlignored);
                     assert(processed);
                 }
             }
         });
     }
 
     threads.join_all();
     while (GetMainSignals().CallbacksPending() > 0) {
         MilliSleep(100);
     }
 
     UnregisterValidationInterface(&sub);
 
     BOOST_CHECK_EQUAL(sub.m_expected_tip, chainActive.Tip()->GetBlockHash());
 }
 
 BOOST_AUTO_TEST_SUITE_END()