diff --git a/src/crypto/base36.cpp b/src/crypto/base36.cpp
index 5a2f157..2264341 100644
--- a/src/crypto/base36.cpp
+++ b/src/crypto/base36.cpp
@@ -7,9 +7,20 @@ namespace fc
     fc::string to_base36( const char* data, size_t len )
     {
        if( len == 0 ) return fc::string();
-       fc::bigint value( data, len );
+
+       const char* src = data;
+       int src_len = len;
+       char buffer[len+1];
+       if (*data & 0x80) {
+           buffer[0] = 0;
+           memcpy( buffer + 1, data, len );
+           src = buffer;
+           src_len++;
+       }
+       fc::bigint value( src, src_len );
+
        auto base36 = "0123456789abcdefghijklmnopqrstuvwxyz";
-       std::vector<char> out( static_cast<size_t>(len * 1.6) + 1 );
+       std::vector<char> out( static_cast<size_t>(len * 1.6) + 2 );
        int pos = out.size() - 1;
        out[pos] = '\0';
        fc::bigint _36(36);
@@ -19,7 +30,7 @@ namespace fc
            out[pos] = base36[(value % _36).to_int64()];
          }
        } while (value /= _36);
-       while (*data++ == 0) {
+       while (len-- > 0 && *data++ == 0) {
            out[--pos] = '0';
        }
        return &out[pos]; //fc::string( &out[pos], out.size() - pos);
@@ -61,7 +72,7 @@ namespace fc
        const char *in = b36.c_str();
        while (*in++ == '0') { leading_zeros++; }
        char* first = bytes.data();
-       while (*first == 0) { first++; len--; }
+       while (len > 0 && *first == 0) { first++; len--; }
        std::vector<char> result;
        result.resize(leading_zeros + len, 0);
        memcpy( result.data() + leading_zeros, first, len );
diff --git a/tests/crypto/base_n_tests.cpp b/tests/crypto/base_n_tests.cpp
index b3e65ac..a501123 100644
--- a/tests/crypto/base_n_tests.cpp
+++ b/tests/crypto/base_n_tests.cpp
@@ -12,6 +12,8 @@
 static const std::string TEST1("");
 static const std::string TEST2("\0\00101", 4);
 static const std::string TEST3("ABCDEFGHIJKLMNOPQRSTUVWXYZ");
+static const std::string TEST4("\377\376\000\375\001\374", 6);
+static const std::string TEST5("\0\0\0", 3);
 
 static void test_16( const std::string& test, const std::string& expected )
 {
@@ -37,6 +39,8 @@ BOOST_AUTO_TEST_CASE(hex_test)
     test_16( TEST1, "" );
     test_16( TEST2, "00013031" );
     test_16( TEST3, "4142434445464748494a4b4c4d4e4f505152535455565758595a" );
+    test_16( TEST4, "fffe00fd01fc" );
+    test_16( TEST5, "000000" );
 }
 
 
@@ -58,6 +62,8 @@ BOOST_AUTO_TEST_CASE(base32_test)
     test_32( TEST1, "" );
     test_32( TEST2, "AAATAMI=" );
     test_32( TEST3, "IFBEGRCFIZDUQSKKJNGE2TSPKBIVEU2UKVLFOWCZLI======" );
+    test_32( TEST4, "777AB7IB7Q======" );
+    test_32( TEST5, "AAAAA===" );
 }
 
 
@@ -79,6 +85,8 @@ BOOST_AUTO_TEST_CASE(base36_test)
     test_36( TEST1, "" );
     test_36( TEST2, "01o35" );
     test_36( TEST3, "l4ksdleyi5pnl0un5raue268ptj43dwjwmz15ie2" );
+    test_36( TEST4, "2rrrvpb7y4" );
+    test_36( TEST5, "000" );
 }
 
 
@@ -112,6 +120,8 @@ BOOST_AUTO_TEST_CASE(base58_test)
     test_58( TEST1, "" );
     test_58( TEST2, "1Q9e" );
     test_58( TEST3, "2zuFXTJSTRK6ESktqhM2QDBkCnH1U46CnxaD" );
+    test_58( TEST4, "3CUeREErf" );
+    test_58( TEST5, "111" );
 }
 
 
@@ -132,6 +142,8 @@ BOOST_AUTO_TEST_CASE(base64_test)
     test_64( TEST1, "" );
     test_64( TEST2, "AAEwMQ==" );
     test_64( TEST3, "QUJDREVGR0hJSktMTU5PUFFSU1RVVldYWVo=" );
+    test_64( TEST4, "//4A/QH8" );
+    test_64( TEST5, "AAAA" );
 }