diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..387e6f6
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,47 @@
+# ---> C++
+# Prerequisites
+*.d
+
+# Compiled Object files
+*.slo
+*.lo
+*.o
+*.obj
+
+# Precompiled Headers
+*.gch
+*.pch
+
+# Compiled Dynamic libraries
+*.so
+*.dylib
+*.dll
+
+# Fortran module files
+*.mod
+*.smod
+
+# Compiled Static libraries
+*.lai
+*.la
+*.a
+*.lib
+
+# Executables
+*.exe
+*.out
+*.app
+
+# Bazel
+bazel-*
+*.bazel*
+WORKSPACE.bazel
+BUILD.bazel
+
+# Dirs
+bin
+obj
+lib
+
+# IDE
+.vscode
diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..9d47866
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,104 @@
+-l =
+
+SHARED ?= false
+DEBUG ?= false
+
+.PHONY: build i install uni uninstall\
+		tools library tests clean
+
+LIB = base
+OBJS =\
+	baseN\
+	hash/sha256\
+
+TOOLS =\
+
+TESTS =\
+
+ifeq (${origin CC}, default)
+CC = g++
+endif
+CFLAGS = -Wall -Wextra -Werror -Wno-unused-result -fPIC
+ifneq (${DEBUG}, false)
+CFLAGS += -fsanitize=address,undefined -g -Og
+-g = -g
+else
+CFLAGS += -O3
+endif
+
+SRCDIR = src
+INCDIR = include
+OBJDIR = obj
+BINDIR = bin
+LIBDIR = lib
+TESTDIR = test
+USRDIR = /usr
+DIRS =\
+	${BINDIR}\
+	${BINDIR}/hash\
+	${OBJDIR}\
+	${OBJDIR}/hash\
+	${LIBDIR}\
+
+build: library tools
+
+i: install
+install: build ${patsubst %, ${USRDIR}/${BINDIR}/btc-%${-g}, ${TOOLS}}\
+	${USRDIR}/${LIBDIR}/lib${LIB}${-g}.a ${USRDIR}/${LIBDIR}/lib${LIB}${-g}.so
+	
+uni: uninstall
+uninstall:
+	rm -f ${USRDIR}/${LIBDIR}/lib${LIB}${-g}.a
+	rm -f ${USRDIR}/${LIBDIR}/lib${LIB}${-g}.so
+	rm -f ${patsubst %, ${USRDIR}/${BINDIR}/btc-%${-g}, ${TOOLS}}
+
+clean:
+	rm -rf ${OBJDIR} ${LIBDIR} ${BINDIR}
+
+ifneq (${OBJS},)
+
+library: ${DIRS} ${LIBDIR}/lib${LIB}${-g}.a ${BINDIR}/lib${LIB}${-g}.so
+
+${OBJDIR}/%${-g}.o: ${SRCDIR}/%.cpp ${INCDIR}/${LIB}/%.hpp
+	${CC} -o $@ -c $< -I${INCDIR} ${-l} ${CFLAGS}
+
+${BINDIR}/lib${LIB}${-g}.so: ${patsubst %, ${OBJDIR}/%${-g}.o, ${OBJS}}
+	${CC} -shared -o $@ $^ 
+
+${LIBDIR}/lib${LIB}${-g}.a: ${patsubst %, ${OBJDIR}/%${-g}.o, ${OBJS}}
+	ar rcs $@ $^
+
+${USRDIR}/${LIBDIR}/lib${LIB}${-g}.so: ${BINDIR}/lib${LIB}${-g}.so
+	cp $< $@
+
+${USRDIR}/${LIBDIR}/lib${LIB}${-g}.a: ${LIBDIR}/lib${LIB}${-g}.a
+	cp $< $@
+
+endif
+ifneq (${TOOLS},)
+
+tools: library ${DIRS} ${patsubst %, ${BINDIR}/%${-g}, ${TOOLS}}
+
+${BINDIR}/%${-g}: ${SRCDIR}/%.cpp ${patsubst %, ${OBJDIR}/%${-g}.o, ${OBJS}}
+ifneq (${SHARED}, false)
+	${CC} -o $@ $< -I${INCDIR} -L${BINDIR} ${-l} -l${LIB}${-g} ${CFLAGS}
+else
+	${CC} -o $@ $< -I${INCDIR} -L${LIBDIR} ${-l} -l${LIB}${-g} ${CFLAGS}
+endif
+
+${USRDIR}/${BINDIR}/btc-%${-g}: ${BINDIR}/%${-g}
+	cp $< $@
+
+endif
+ifneq (${TESTS},)
+
+tests: library ${DIRS} ${patsubst %, ${BINDIR}/%${-g}, ${TESTS}}
+	${patsubst %, ./${BINDIR}/%${-g};, ${TESTS}}
+
+${BINDIR}/%${-g}: ${TESTDIR}/%.cpp ${patsubst %, ${OBJDIR}/%${-g}.o, ${OBJS}}
+	${CC} -o $@ $< -I${INCDIR} -L${LIBDIR} ${-l} -l${LIB}${-g} -lgtest ${CFLAGS}
+
+endif
+
+${DIRS}:
+	mkdir $@
\ No newline at end of file
diff --git a/include/base/baseN.hpp b/include/base/baseN.hpp
new file mode 100644
index 0000000..66fca92
--- /dev/null
+++ b/include/base/baseN.hpp
@@ -0,0 +1,12 @@
+#pragma once
+
+#include <cstdint>
+#include <string>
+#include <vector>
+
+namespace baseN
+{
+    bool isValid(const std::string &str, const int8_t *map) noexcept;
+    std::string encode(std::vector<uint8_t> data, uint8_t base, uint64_t enc_size, const char *digits) noexcept;
+    std::vector<uint8_t> decode(const std::string &str, uint8_t base, uint64_t dec_size, const char *digits, const int8_t *map);
+}
\ No newline at end of file
diff --git a/include/base/hash/sha256.hpp b/include/base/hash/sha256.hpp
new file mode 100644
index 0000000..c2e51f3
--- /dev/null
+++ b/include/base/hash/sha256.hpp
@@ -0,0 +1,10 @@
+#pragma once
+
+#include <cstdint>
+#include <vector>
+
+#define SHA256_DIGEST_LENGTH 32
+
+namespace hash {
+	std::vector<uint8_t> sha256(const std::vector<uint8_t> &data);
+}
\ No newline at end of file
diff --git a/src/baseN.cpp b/src/baseN.cpp
new file mode 100644
index 0000000..2c5b498
--- /dev/null
+++ b/src/baseN.cpp
@@ -0,0 +1,112 @@
+#include <stdexcept>
+
+#include <base/baseN.hpp>
+
+namespace baseN
+{
+    bool isValid(const std::string &str, const int8_t *map) noexcept
+    {
+        for (int64_t i = str.size() - 1; i >= 0; i--)
+        {
+            if (map[(int8_t)str[i]] == -1)
+            {
+                return false;
+            }
+        }
+        return true;
+    }
+    std::string encode(std::vector<uint8_t> data, uint8_t base, uint64_t enc_size, const char *digits) noexcept
+    {
+        if (data.size() == 0)
+        {
+            return "";
+        }
+        std::string str(enc_size, ' ');
+        int64_t
+            zero_count = 0,
+            idx_div = 0,
+            idx_quo = 0,
+            idx_quo_last = data.size(),
+            idx_str = str.size() - 1;
+        uint16_t div = data[idx_div++];
+
+        while (data[zero_count] == 0)
+        {
+            zero_count++;
+        }
+        while (idx_quo_last > 1 || data[0] > base)
+        {
+            if (div < base)
+            {
+                div <<= 8;
+                div += data[idx_div++];
+            }
+            data[idx_quo++] = div / base;
+            div %= base;
+            while (idx_div < idx_quo_last)
+            {
+                div <<= 8;
+                div += data[idx_div++];
+                data[idx_quo++] = div / base;
+                div %= base;
+            }
+            idx_quo_last = idx_quo;
+            idx_quo = 0;
+            idx_div = 0;
+            str[idx_str--] = digits[div];
+            div = data[idx_div++];
+        }
+        str[idx_str--] = digits[div];
+        while (zero_count > 0 && idx_str > 0)
+        {
+            str[idx_str--] = '1';
+            zero_count--;
+        }
+        str.erase(0, idx_str + 1);
+        return str;
+    }
+    std::vector<uint8_t> decode(const std::string &str, uint8_t base, uint64_t dec_size, const char *digits, const int8_t *map)
+    {
+        if (str.size() == 0)
+        {
+            return std::vector<uint8_t>();
+        }
+        if (!baseN::isValid(str, map))
+        {
+            throw std::logic_error("baseN::decode: out of digits map");
+        }
+        std::vector<uint8_t> data(dec_size);
+        uint64_t idx_str = 0;
+        int64_t
+            zero_count = 0,
+            idx_quo = data.size() - 1,
+            idx_quo_last = data.size() - 2;
+        uint16_t div;
+
+        while (str[zero_count] == digits[0])
+        {
+            zero_count++;
+        }
+        data[idx_quo] = map[(int8_t)str[idx_str++]];
+        while (idx_str < str.size())
+        {
+            div = map[(int8_t)str[idx_str++]];
+            while (idx_quo > idx_quo_last && idx_quo > 0)
+            {
+                div += data[idx_quo] * base;
+                data[idx_quo--] = div;
+                div >>= 8;  
+            }
+            data[idx_quo--] = div;
+            idx_quo_last = idx_quo;
+            idx_quo = data.size() - 1;
+        }
+        idx_quo = 0;
+        while (data[idx_quo] == 0)
+        {
+            idx_quo++;
+        }
+        data.erase(data.begin(), data.begin() + idx_quo - zero_count);
+        return data;
+    }
+}
\ No newline at end of file
diff --git a/src/hash/sha256.cpp b/src/hash/sha256.cpp
new file mode 100644
index 0000000..fd4d82a
--- /dev/null
+++ b/src/hash/sha256.cpp
@@ -0,0 +1,175 @@
+/*********************************************************************
+* Filename:   sha256.c
+* Author:     Brad Conte (brad AT bradconte.com)
+* Copyright:
+* Disclaimer: This code is presented "as is" without any guarantees.
+* Details:    Implementation of the SHA-256 hashing algorithm.
+              SHA-256 is one of the three algorithms in the SHA2
+              specification. The others, SHA-384 and SHA-512, are not
+              offered in this implementation.
+              Algorithm specification can be found here:
+               * http://csrc.nist.gov/publications/fips/fips180-2/fips180-2withchangenotice.pdf
+              This implementation uses little endian byte order.
+*********************************************************************/
+
+#include <memory.h>
+#include <stdlib.h>
+
+#include <base/hash/sha256.hpp>
+
+#define ROTLEFT(a,b) (((a) << (b)) | ((a) >> (32-(b))))
+#define ROTRIGHT(a,b) (((a) >> (b)) | ((a) << (32-(b))))
+
+#define CH(x,y,z) (((x) & (y)) ^ (~(x) & (z)))
+#define MAJ(x,y,z) (((x) & (y)) ^ ((x) & (z)) ^ ((y) & (z)))
+#define EP0(x) (ROTRIGHT(x,2) ^ ROTRIGHT(x,13) ^ ROTRIGHT(x,22))
+#define EP1(x) (ROTRIGHT(x,6) ^ ROTRIGHT(x,11) ^ ROTRIGHT(x,25))
+#define SIG0(x) (ROTRIGHT(x,7) ^ ROTRIGHT(x,18) ^ ((x) >> 3))
+#define SIG1(x) (ROTRIGHT(x,17) ^ ROTRIGHT(x,19) ^ ((x) >> 10))
+
+struct SHA256_CTX{
+	uint8_t data[64];
+	uint32_t datalen;
+	unsigned long long bitlen;
+	uint32_t state[8];
+};
+
+static const uint32_t k[64] = {
+	0x428a2f98,0x71374491,0xb5c0fbcf,0xe9b5dba5,0x3956c25b,0x59f111f1,0x923f82a4,0xab1c5ed5,
+	0xd807aa98,0x12835b01,0x243185be,0x550c7dc3,0x72be5d74,0x80deb1fe,0x9bdc06a7,0xc19bf174,
+	0xe49b69c1,0xefbe4786,0x0fc19dc6,0x240ca1cc,0x2de92c6f,0x4a7484aa,0x5cb0a9dc,0x76f988da,
+	0x983e5152,0xa831c66d,0xb00327c8,0xbf597fc7,0xc6e00bf3,0xd5a79147,0x06ca6351,0x14292967,
+	0x27b70a85,0x2e1b2138,0x4d2c6dfc,0x53380d13,0x650a7354,0x766a0abb,0x81c2c92e,0x92722c85,
+	0xa2bfe8a1,0xa81a664b,0xc24b8b70,0xc76c51a3,0xd192e819,0xd6990624,0xf40e3585,0x106aa070,
+	0x19a4c116,0x1e376c08,0x2748774c,0x34b0bcb5,0x391c0cb3,0x4ed8aa4a,0x5b9cca4f,0x682e6ff3,
+	0x748f82ee,0x78a5636f,0x84c87814,0x8cc70208,0x90befffa,0xa4506ceb,0xbef9a3f7,0xc67178f2
+};
+
+static void sha256_transform(SHA256_CTX *ctx, const uint8_t *data)
+{
+	uint32_t a, b, c, d, e, f, g, h, i, j, t1, t2, m[64];
+
+	for (i = 0, j = 0; i < 16; ++i, j += 4)
+		m[i] = (data[j] << 24) | (data[j + 1] << 16) | (data[j + 2] << 8) | (data[j + 3]);
+	for ( ; i < 64; ++i)
+		m[i] = SIG1(m[i - 2]) + m[i - 7] + SIG0(m[i - 15]) + m[i - 16];
+
+	a = ctx->state[0];
+	b = ctx->state[1];
+	c = ctx->state[2];
+	d = ctx->state[3];
+	e = ctx->state[4];
+	f = ctx->state[5];
+	g = ctx->state[6];
+	h = ctx->state[7];
+
+	for (i = 0; i < 64; ++i) {
+		t1 = h + EP1(e) + CH(e,f,g) + k[i] + m[i];
+		t2 = EP0(a) + MAJ(a,b,c);
+		h = g;
+		g = f;
+		f = e;
+		e = d + t1;
+		d = c;
+		c = b;
+		b = a;
+		a = t1 + t2;
+	}
+
+	ctx->state[0] += a;
+	ctx->state[1] += b;
+	ctx->state[2] += c;
+	ctx->state[3] += d;
+	ctx->state[4] += e;
+	ctx->state[5] += f;
+	ctx->state[6] += g;
+	ctx->state[7] += h;
+}
+
+static void sha256_init(SHA256_CTX *ctx)
+{
+	ctx->datalen = 0;
+	ctx->bitlen = 0;
+	ctx->state[0] = 0x6a09e667;
+	ctx->state[1] = 0xbb67ae85;
+	ctx->state[2] = 0x3c6ef372;
+	ctx->state[3] = 0xa54ff53a;
+	ctx->state[4] = 0x510e527f;
+	ctx->state[5] = 0x9b05688c;
+	ctx->state[6] = 0x1f83d9ab;
+	ctx->state[7] = 0x5be0cd19;
+}
+
+static void sha256_update(SHA256_CTX *ctx, const uint8_t *data, size_t len)
+{
+	uint32_t i;
+
+	for (i = 0; i < len; ++i) {
+		ctx->data[ctx->datalen] = data[i];
+		ctx->datalen++;
+		if (ctx->datalen == 64) {
+			sha256_transform(ctx, ctx->data);
+			ctx->bitlen += 512;
+			ctx->datalen = 0;
+		}
+	}
+}
+
+static void sha256_final(SHA256_CTX *ctx, uint8_t *hash)
+{
+	uint32_t i;
+
+	i = ctx->datalen;
+
+	// Pad whatever data is left in the buffer.
+	if (ctx->datalen < 56) {
+		ctx->data[i++] = 0x80;
+		while (i < 56)
+			ctx->data[i++] = 0x00;
+	}
+	else {
+		ctx->data[i++] = 0x80;
+		while (i < 64)
+			ctx->data[i++] = 0x00;
+		sha256_transform(ctx, ctx->data);
+		memset(ctx->data, 0, 56);
+	}
+
+	// Append to the padding the total message's length in bits and transform.
+	ctx->bitlen += ctx->datalen * 8;
+	ctx->data[63] = ctx->bitlen;
+	ctx->data[62] = ctx->bitlen >> 8;
+	ctx->data[61] = ctx->bitlen >> 16;
+	ctx->data[60] = ctx->bitlen >> 24;
+	ctx->data[59] = ctx->bitlen >> 32;
+	ctx->data[58] = ctx->bitlen >> 40;
+	ctx->data[57] = ctx->bitlen >> 48;
+	ctx->data[56] = ctx->bitlen >> 56;
+	sha256_transform(ctx, ctx->data);
+
+	// Since this implementation uses little endian byte ordering and SHA uses big endian,
+	// reverse all the bytes when copying the final state to the output hash.
+	for (i = 0; i < 4; ++i) {
+		hash[i]      = (ctx->state[0] >> (24 - i * 8)) & 0x000000ff;
+		hash[i + 4]  = (ctx->state[1] >> (24 - i * 8)) & 0x000000ff;
+		hash[i + 8]  = (ctx->state[2] >> (24 - i * 8)) & 0x000000ff;
+		hash[i + 12] = (ctx->state[3] >> (24 - i * 8)) & 0x000000ff;
+		hash[i + 16] = (ctx->state[4] >> (24 - i * 8)) & 0x000000ff;
+		hash[i + 20] = (ctx->state[5] >> (24 - i * 8)) & 0x000000ff;
+		hash[i + 24] = (ctx->state[6] >> (24 - i * 8)) & 0x000000ff;
+		hash[i + 28] = (ctx->state[7] >> (24 - i * 8)) & 0x000000ff;
+	}	
+}
+
+namespace btc::hash
+{
+	std::vector<uint8_t> sha256(const std::vector<uint8_t> &data)
+	{
+		std::vector<uint8_t> hash(SHA256_DIGEST_LENGTH);
+		SHA256_CTX ctx;
+		sha256_init(&ctx);
+		sha256_update(&ctx, data.data(), data.size());
+		sha256_final(&ctx, hash.data());
+		return hash;
+	}
+}
\ No newline at end of file