diff --git a/src/core/libs/osnma_msg_receiver.cc b/src/core/libs/osnma_msg_receiver.cc
index 756b89b5b..759c2db0b 100644
--- a/src/core/libs/osnma_msg_receiver.cc
+++ b/src/core/libs/osnma_msg_receiver.cc
@@ -18,14 +18,18 @@
 
 
 #include "osnma_msg_receiver.h"
-#include "display.h"                // for colors in terminal
 #include "gnss_sdr_make_unique.h"   // for std::make_unique in C++11
 #include <glog/logging.h>           // for DLOG
 #include <gnuradio/io_signature.h>  // for gr::io_signature::make
 #include <bitset>
+#include <cstddef>
 #include <cstdint>
 #include <iostream>
+#include <iterator>
+#include <numeric>
 #include <typeinfo>  // for typeid
+#include <unordered_map>
+#include <utility>
 
 #if HAS_GENERIC_LAMBDA
 #else
@@ -40,6 +44,96 @@ namespace wht = boost;
 namespace wht = std;
 #endif
 
+
+// OSNMA SIS ICD v1.0 Table 3
+const std::unordered_map<uint8_t, std::pair<uint16_t, uint16_t>> OSNMA_TABLE_3 = {
+    {0, {0, 0}},
+    {1, {0, 0}},
+    {2, {0, 0}},
+    {3, {0, 0}},
+    {4, {0, 0}},
+    {5, {0, 0}},
+    {6, {0, 0}},
+    {7, {13, 1352}},
+    {8, {14, 1456}},
+    {9, {15, 1560}},
+    {10, {16, 1664}},
+    {11, {0, 0}},
+    {12, {0, 0}},
+    {13, {0, 0}},
+    {14, {0, 0}},
+    {15, {0, 0}}};  // key: nb_dp, value: {num_blocks, l_dp_bits}
+
+const std::unordered_map<uint8_t, std::string> OSNMA_TABLE_5 = {
+    {0, std::string("Reserved")},
+    {1, std::string("ECDSA P-256")},
+    {2, std::string("Reserved")},
+    {3, std::string("ECDSA P-521")},
+    {4, std::string("OAM")},
+    {5, std::string("Reserved")},
+    {6, std::string("Reserved")},
+    {7, std::string("Reserved")},
+    {8, std::string("Reserved")},
+    {9, std::string("Reserved")},
+    {10, std::string("Reserved")},
+    {11, std::string("Reserved")},
+    {12, std::string("Reserved")},
+    {13, std::string("Reserved")},
+    {14, std::string("Reserved")},
+    {15, std::string("Reserved")}};  // key: nptk, value: message
+
+const std::unordered_map<std::string, uint16_t> OSNMA_TABLE_6 = {
+    {std::string("ECDSA P-256"), 264},
+    {std::string("ECDSA P-521"), 536}};
+
+// OSNMA SIS ICD v1.0 Table 7
+const std::unordered_map<uint8_t, std::pair<uint16_t, uint16_t>> OSNMA_TABLE_7 = {
+    {0, {0, 0}},
+    {1, {7, 728}},
+    {2, {8, 832}},
+    {3, {9, 936}},
+    {4, {10, 1040}},
+    {5, {11, 1144}},
+    {6, {12, 1248}},
+    {7, {13, 1352}},
+    {8, {14, 1456}},
+    {9, {0, 0}},
+    {10, {0, 0}},
+    {11, {0, 0}},
+    {12, {0, 0}},
+    {13, {0, 0}},
+    {14, {0, 0}},
+    {15, {0, 0}}};  // key: nb_dk, value: {num_blocks, l_dk_bits}
+
+const std::unordered_map<uint8_t, std::string> OSNMA_TABLE_8 = {
+    {0, std::string("SHA-256")},
+    {1, std::string("Reserved")},
+    {2, std::string("SHA3-256")},
+    {3, std::string("Reserved")}};  // key: hs, value: hash_function
+
+const std::unordered_map<uint8_t, uint16_t> OSNMA_TABLE_10 = {
+    {0, 96},
+    {1, 104},
+    {2, 112},
+    {3, 120},
+    {4, 128},
+    {5, 160},
+    {6, 192},
+    {7, 224},
+    {8, 256},
+    {9, 0},
+    {10, 0},
+    {11, 0},
+    {12, 0},
+    {13, 0},
+    {15, 0},
+    {15, 0}};  // key: ks, value: lk_bits
+
+const std::unordered_map<std::string, std::pair<uint16_t, uint16_t>> OSNMA_TABLE_15 = {
+    {std::string("ECDSA P-256"), {512, 256}},
+    {std::string("ECDSA P-521"), {1059, 521}}};  // key: ECDSA Curve and hash function, value: {l_ds_bits, key_lenght_bits}
+
+
 osnma_msg_receiver_sptr osnma_msg_receiver_make()
 {
     return osnma_msg_receiver_sptr(new osnma_msg_receiver());
@@ -101,11 +195,12 @@ void osnma_msg_receiver::msg_handler_osnma(const pmt::pmt_t& msg)
 }
 
 
-void osnma_msg_receiver::process_osnma_message(std::shared_ptr<OSNMA_msg> osnma_msg)
+void osnma_msg_receiver::process_osnma_message(const std::shared_ptr<OSNMA_msg>& osnma_msg)
 {
     const auto hkroot_msg = osnma_msg->hkroot;
     read_nma_header(hkroot_msg[0]);
     read_dsm_header(hkroot_msg[1]);
+    read_dsm_block(osnma_msg);
 }
 
 
@@ -122,4 +217,147 @@ void osnma_msg_receiver::read_dsm_header(uint8_t dsm_header)
 {
     d_osnma_data.d_dsm_header.dsm_id = (dsm_header & 0b11110000) >> 4;
     d_osnma_data.d_dsm_header.dsm_block_id = dsm_header & 0b00001111;  // BID
-}
\ No newline at end of file
+}
+
+
+void osnma_msg_receiver::read_dsm_block(const std::shared_ptr<OSNMA_msg>& osnma_msg)
+{
+    size_t i = 0;
+    for (auto it = osnma_msg->hkroot.cbegin() + 2; it != osnma_msg->hkroot.cend(); ++it)
+        {
+            d_dsm_message[d_osnma_data.d_dsm_header.dsm_id][13 * d_osnma_data.d_dsm_header.dsm_block_id + i] = *it;
+            i++;
+        }
+    if (d_osnma_data.d_dsm_header.dsm_block_id == 0)
+        {
+            // Get number of blocks in message
+            uint8_t nb = (osnma_msg->hkroot[2] & 0b11110000) >> 4;
+            uint16_t number_of_blocks = 0;
+            if (d_osnma_data.d_dsm_header.dsm_id >= 0 && d_osnma_data.d_dsm_header.dsm_id < 12)
+                {
+                    // Table 3
+                    const auto it = OSNMA_TABLE_3.find(nb);
+                    if (it != OSNMA_TABLE_3.cend())
+                        {
+                            number_of_blocks = it->second.first;
+                        }
+                }
+            else if (d_osnma_data.d_dsm_header.dsm_id >= 12 && d_osnma_data.d_dsm_header.dsm_id < 16)
+                {
+                    // Table 7
+                    const auto it = OSNMA_TABLE_7.find(nb);
+                    if (it != OSNMA_TABLE_7.cend())
+                        {
+                            number_of_blocks = it->second.first;
+                        }
+                }
+
+            d_number_of_blocks[d_osnma_data.d_dsm_header.dsm_id] = number_of_blocks;
+        }
+    // Annotate bid
+    d_dsm_id_received[d_osnma_data.d_dsm_header.dsm_id][d_osnma_data.d_dsm_header.dsm_block_id] = 1;
+    // is message complete? -> process_dsm_message(osnma_msg)
+    if ((d_number_of_blocks[d_osnma_data.d_dsm_header.dsm_id] != 0) && (d_number_of_blocks[d_osnma_data.d_dsm_header.dsm_id] == std::accumulate(d_dsm_id_received[d_osnma_data.d_dsm_header.dsm_id].begin(), d_dsm_id_received[d_osnma_data.d_dsm_header.dsm_id].end(), 0)))
+        {
+            std::vector<uint8_t> dsm_msg(std::size_t(d_number_of_blocks[d_osnma_data.d_dsm_header.dsm_id]) * 13, 0);
+            for (uint32_t i = 0; i < d_number_of_blocks[d_osnma_data.d_dsm_header.dsm_id]; i++)
+                {
+                    for (uint32_t j = 0; j < 14; j++)
+                        {
+                            dsm_msg[i * 13 + j] = d_dsm_message[d_osnma_data.d_dsm_header.dsm_id][i * 13 + j];
+                        }
+                }
+            process_dsm_message(osnma_msg, dsm_msg);
+        }
+}
+
+
+void osnma_msg_receiver::process_dsm_message(const std::shared_ptr<OSNMA_msg>& osnma_msg, const std::vector<uint8_t>& dsm_msg)
+{
+    if (d_osnma_data.d_dsm_header.dsm_id >= 0 && d_osnma_data.d_dsm_header.dsm_id < 12)
+        {
+            // DSM-KROOT message
+            d_osnma_data.d_dsm_kroot_message.nb_dk = (dsm_msg[0] & 0b11110000) >> 4;
+            d_osnma_data.d_dsm_kroot_message.pkid = (dsm_msg[0] & 0b00001111);
+            d_osnma_data.d_dsm_kroot_message.cidkr = (dsm_msg[1] & 0b11000000) >> 6;
+            d_osnma_data.d_dsm_kroot_message.reserved1 = (dsm_msg[1] & 0b00110000) >> 4;
+            d_osnma_data.d_dsm_kroot_message.hf = (dsm_msg[1] & 0b00001100) >> 2;
+
+            d_osnma_data.d_dsm_kroot_message.mf = (dsm_msg[1] & 0b00000011);
+            d_osnma_data.d_dsm_kroot_message.ks = (dsm_msg[2] & 0b11110000) >> 4;
+            d_osnma_data.d_dsm_kroot_message.ts = (dsm_msg[2] & 0b00001111);
+            d_osnma_data.d_dsm_kroot_message.maclt = dsm_msg[3];
+            d_osnma_data.d_dsm_kroot_message.reserved = (dsm_msg[4] & 0b11110000) >> 4;
+            d_osnma_data.d_dsm_kroot_message.wn_k = static_cast<uint16_t>((dsm_msg[4] & 0b00001111) << 8) +
+                                                    static_cast<uint16_t>(dsm_msg[5]);
+            d_osnma_data.d_dsm_kroot_message.towh_k = dsm_msg[6];
+
+            uint32_t lk = 0;
+            const auto it = OSNMA_TABLE_10.find(d_osnma_data.d_dsm_kroot_message.ks);
+            if (it != OSNMA_TABLE_10.cend())
+                {
+                    lk = it->second;
+                }
+
+            d_osnma_data.d_dsm_kroot_message.alpha = (static_cast<uint64_t>(dsm_msg[7]) << 40) +
+                                                     (static_cast<uint64_t>(dsm_msg[8]) << 32) +
+                                                     (static_cast<uint64_t>(dsm_msg[9]) << 24) +
+                                                     (static_cast<uint64_t>(dsm_msg[10]) << 16) +
+                                                     (static_cast<uint64_t>(dsm_msg[11]) << 8) +
+                                                     static_cast<uint64_t>(dsm_msg[12]);
+            uint32_t bytes_lk = lk / 8;
+            d_osnma_data.d_dsm_kroot_message.kroot = std::vector<uint8_t>(bytes_lk, 0);
+            for (uint32_t k = 0; k < bytes_lk; k++)
+                {
+                    d_osnma_data.d_dsm_kroot_message.kroot[k] = dsm_msg[13 + k];
+                }
+            // uint32_t l_ld = 0;
+            //  const auto it2 = OSNMA_TABLE_5.find()
+            //   d_osnma_data.d_dsm_kroot_message.ds = "0";
+            //  d_osnma_data.d_dsm_kroot_message.p_dk;
+        }
+    else if (d_osnma_data.d_dsm_header.dsm_id >= 12 && d_osnma_data.d_dsm_header.dsm_id < 16)
+        {
+            // DSM-PKR message
+            d_osnma_data.d_dsm_pkr_message.nb_dp = (dsm_msg[0] & 0b11110000) >> 4;
+            d_osnma_data.d_dsm_pkr_message.mid = (dsm_msg[0] & 0b00001111);
+            for (int k = 0; k > 128; k++)
+                {
+                    d_osnma_data.d_dsm_pkr_message.itn[k] = dsm_msg[k + 1];
+                }
+
+            d_osnma_data.d_dsm_pkr_message.npkt = (dsm_msg[129] & 0b11110000) >> 4;
+            d_osnma_data.d_dsm_pkr_message.npktid = (dsm_msg[129] & 0b00001111);
+
+            // Table 5
+            uint32_t l_npk = 0;
+            const auto it = OSNMA_TABLE_5.find(d_osnma_data.d_dsm_pkr_message.npkt);
+            if (it != OSNMA_TABLE_5.cend())
+                {
+                    const auto it2 = OSNMA_TABLE_6.find(it->second);
+                    if (it2 != OSNMA_TABLE_6.cend())
+                        {
+                            l_npk = it2->second / 8;
+                        }
+                }
+
+            if (d_osnma_data.d_dsm_pkr_message.npkt == 4)
+                {
+                    // OAM
+                    l_npk = 0;  // ?
+                }
+
+            d_osnma_data.d_dsm_pkr_message.npk = std::vector<uint8_t>(l_npk, 0);
+            for (uint32_t k = 0; k > l_npk; k++)
+                {
+                    d_osnma_data.d_dsm_pkr_message.npk[k] = dsm_msg[k + 130];
+                }
+            uint32_t l_dp = dsm_msg.size();
+            uint32_t l_pd = l_dp - 130 - l_npk;
+            d_osnma_data.d_dsm_pkr_message.p_dp = std::vector<uint8_t>(l_pd, 0);
+            for (uint32_t k = 0; k > l_pd; k++)
+                {
+                    d_osnma_data.d_dsm_pkr_message.p_dp[k] = dsm_msg[l_dp - l_pd + k];
+                }
+        }
+}
diff --git a/src/core/libs/osnma_msg_receiver.h b/src/core/libs/osnma_msg_receiver.h
index b9b51293b..ba51a874b 100644
--- a/src/core/libs/osnma_msg_receiver.h
+++ b/src/core/libs/osnma_msg_receiver.h
@@ -24,8 +24,9 @@
 #include "osnma_data.h"            // for OSNMA_data
 #include <gnuradio/block.h>        // for gr::block
 #include <pmt/pmt.h>               // for pmt::pmt_t
+#include <array>                   // for std::array
 #include <memory>                  // for std::shared_ptr
-
+#include <vector>
 
 /** \addtogroup Core
  * \{ */
@@ -54,10 +55,15 @@ private:
     osnma_msg_receiver();
 
     void msg_handler_osnma(const pmt::pmt_t& msg);
-    void process_osnma_message(std::shared_ptr<OSNMA_msg> osnma_msg);
+    void process_osnma_message(const std::shared_ptr<OSNMA_msg>& osnma_msg);
     void read_nma_header(uint8_t nma_header);
     void read_dsm_header(uint8_t dsm_header);
+    void read_dsm_block(const std::shared_ptr<OSNMA_msg>& osnma_msg);
+    void process_dsm_message(const std::shared_ptr<OSNMA_msg>& osnma_msg, const std::vector<uint8_t>& dsm_msg);
 
+    std::array<std::array<uint8_t, 256>, 16> d_dsm_message{};
+    std::array<std::array<uint8_t, 16>, 16> d_dsm_id_received{};
+    std::array<uint16_t, 16> d_number_of_blocks{};
     OSNMA_data d_osnma_data{};
     bool d_new_data{false};
 };
diff --git a/src/core/system_parameters/osnma_data.h b/src/core/system_parameters/osnma_data.h
index 3fa6b6232..966e425ac 100644
--- a/src/core/system_parameters/osnma_data.h
+++ b/src/core/system_parameters/osnma_data.h
@@ -42,6 +42,36 @@ struct dsm_header
     uint8_t dsm_block_id;
 };
 
+struct DSM_PKR_message
+{
+    uint8_t nb_dp;
+    uint8_t mid;
+    std::array<uint8_t, 128> itn;  // bitset<1024>
+    uint8_t npkt;
+    uint8_t npktid;
+    std::vector<uint8_t> npk;
+    std::vector<uint8_t> p_dp;
+};
+
+struct DSM_KROOT_message
+{
+    uint8_t nb_dk;
+    uint8_t pkid;
+    uint8_t cidkr;
+    uint8_t reserved1;
+    uint8_t hf;
+    uint8_t mf;
+    uint8_t ks;
+    uint8_t ts;
+    uint8_t maclt;
+    uint8_t reserved;
+    uint16_t wn_k;
+    uint8_t towh_k;
+    uint64_t alpha;
+    std::vector<uint8_t> kroot;
+    std::vector<uint8_t> ds;
+    std::vector<uint8_t> p_dk;
+};
 
 /*!
  * \brief This class handles ONSMA data
@@ -51,16 +81,10 @@ class OSNMA_data
 {
 public:
     OSNMA_data() = default;
-
-    std::string itn;  // bitset<1024>
-    std::string npk;
-    std::string p_dp;
     nma_header d_nma_header;
     dsm_header d_dsm_header;
-    uint8_t nb_dp;
-    uint8_t mid;
-    uint8_t npkt;
-    uint8_t npktid;
+    DSM_PKR_message d_dsm_pkr_message;
+    DSM_KROOT_message d_dsm_kroot_message;
 };