diff --git a/CMakeLists.txt b/CMakeLists.txt
index fbd812c..d8ad7c8 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -5,6 +5,6 @@ set(CMAKE_C_STANDARD 99)
 add_compile_definitions(__STDC_FORMAT_MACROS=1)
 
 add_library(libdicformat SHARED include/dicformat/consts.h include/dicformat/enums.h include/dic.h include/dicformat.h
-            include/dicformat/decls.h include/dicformat/structs.h src/identify.c src/open.c include/dicformat/context.h src/close.c include/dicformat/errors.h src/read.c)
+            include/dicformat/decls.h include/dicformat/structs.h src/identify.c src/open.c include/dicformat/context.h src/close.c include/dicformat/errors.h src/read.c src/crc64.c)
 
 include_directories(include include/dicformat)
\ No newline at end of file
diff --git a/include/dicformat/consts.h b/include/dicformat/consts.h
index f254cce..28d024c 100644
--- a/include/dicformat/consts.h
+++ b/include/dicformat/consts.h
@@ -56,6 +56,9 @@
 /** This mask is to check for position in CompactDisc suffix/prefix deduplicated block */
 #define CD_DFIX_MASK 0x00FFFFFF
 
+#define CRC64_ECMA_POLY 0xC96C5795D7870F42
+#define CRC64_ECMA_SEED 0xFFFFFFFFFFFFFFFF
+
 #endif //LIBDICFORMAT_CONSTS_H
 
 #pragma clang diagnostic pop
\ No newline at end of file
diff --git a/include/dicformat/decls.h b/include/dicformat/decls.h
index a414cf8..ae02976 100644
--- a/include/dicformat/decls.h
+++ b/include/dicformat/decls.h
@@ -46,5 +46,16 @@ int close(void *context);
 
 uint8_t *read_media_tag(void *context, int tag);
 
+void *crc64_init(uint64_t polynomial, uint64_t seed);
+
+void *crc64_init_ecma(void);
+
+void crc64_update(void *context, const char *data, size_t len);
+
+uint64_t crc64_final(void *context);
+
+uint64_t crc64_data(const char *data, size_t len, uint64_t polynomial, uint64_t seed);
+
+uint64_t crc64_data_ecma(const char *data, size_t len);
 
 #endif //LIBDICFORMAT_DECLS_H
diff --git a/include/dicformat/structs.h b/include/dicformat/structs.h
index d7087bd..4db007c 100644
--- a/include/dicformat/structs.h
+++ b/include/dicformat/structs.h
@@ -302,6 +302,12 @@ typedef struct ChecksumEntry
     uint32_t length;
 } ChecksumEntry;
 
+typedef struct Crc64Context
+{
+    uint64_t finalSeed;
+    uint64_t table[256];
+    uint64_t hashInt;
+} Crc64Context;
 
 #pragma pack(pop)
 
diff --git a/src/crc64.c b/src/crc64.c
new file mode 100644
index 0000000..275f16a
--- /dev/null
+++ b/src/crc64.c
@@ -0,0 +1,115 @@
+// /***************************************************************************
+// The Disc Image Chef
+// ----------------------------------------------------------------------------
+//
+// Filename       : crc64.c
+// Author(s)      : Natalia Portillo <claunia@claunia.com>
+//
+// Component      : Checksums.
+//
+// --[ Description ] ----------------------------------------------------------
+//
+//     Implements a CRC64 algorithm.
+//
+// --[ License ] --------------------------------------------------------------
+//
+//     This library is free software; you can redistribute it and/or modify
+//     it under the terms of the GNU Lesser General Public License as
+//     published by the Free Software Foundation; either version 2.1 of the
+//     License, or (at your option) any later version.
+//
+//     This library is distributed in the hope that it will be useful, but
+//     WITHOUT ANY WARRANTY; without even the implied warranty of
+//     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+//     Lesser General Public License for more details.
+//
+//     You should have received a copy of the GNU Lesser General Public
+//     License along with this library; if not, see <http://www.gnu.org/licenses/>.
+//
+// ----------------------------------------------------------------------------
+// Copyright © 2011-2019 Natalia Portillo
+// ****************************************************************************/
+
+#include <stdint.h>
+#include <malloc.h>
+#include <string.h>
+#include <dicformat.h>
+
+void *crc64_init(uint64_t polynomial, uint64_t seed)
+{
+    Crc64Context *ctx;
+
+    ctx = malloc(sizeof(Crc64Context));
+
+    if(ctx == NULL)
+        return NULL;
+
+    memset(ctx, 1, sizeof(Crc64Context));
+
+    ctx->finalSeed = seed;
+    ctx->hashInt   = seed;
+
+    for(int i = 0; i < 256; i++)
+    {
+        uint64_t entry = (uint64_t)i;
+        for(int  j     = 0; j < 8; j++)
+            if((entry & 1) == 1)
+                entry = (entry >> 1) ^ polynomial;
+            else
+                entry = entry >> 1;
+
+        ctx->table[i] = entry;
+    }
+
+    return ctx;
+}
+
+void *crc64_init_ecma(void)
+{
+    return crc64_init(CRC64_ECMA_POLY, CRC64_ECMA_SEED);
+}
+
+
+void crc64_update(void *context, const char *data, size_t len)
+{
+    Crc64Context *ctx = context;
+
+    for(size_t i = 0; i < len; i++)
+        ctx->hashInt = (ctx->hashInt >> 8) ^ ctx->table[data[i] ^ (ctx->hashInt & 0xFF)];
+}
+
+uint64_t crc64_final(void *context)
+{
+    Crc64Context *ctx = context;
+
+    return ctx->hashInt ^ ctx->finalSeed;
+}
+
+uint64_t crc64_data(const char *data, size_t len, uint64_t polynomial, uint64_t seed)
+{
+    uint64_t table[256];
+    uint64_t hashInt = seed;
+
+    for(int i = 0; i < 256; i++)
+    {
+        uint64_t entry = (uint64_t)i;
+        for(int  j     = 0; j < 8; j++)
+            if((entry & 1) == 1)
+                entry = (entry >> 1) ^ polynomial;
+            else
+                entry = entry >> 1;
+
+        table[i] = entry;
+    }
+
+    for(size_t i = 0; i < len; i++)
+        hashInt = (hashInt >> 8) ^ table[data[i] ^ (hashInt & 0xFF)];
+
+    return hashInt ^ seed;
+}
+
+uint64_t crc64_data_ecma(const char *data, size_t len)
+{
+    return crc64_data(data, len, CRC64_ECMA_POLY, CRC64_ECMA_SEED);
+}
+