diff --git a/Makefile b/Makefile
index 24810b13d3..43049aafe4 100644
--- a/Makefile
+++ b/Makefile
@@ -1,6 +1,6 @@
 CC     = gcc
 CFLAGS = -Wall -Os
-OBJS   = bignum.o ecdsa.o secp256k1.o sha2.o rand.o hmac.o bip32.o ripemd160.o
+OBJS   = bignum.o ecdsa.o secp256k1.o sha2.o rand.o hmac.o bip32.o ripemd160.o bip39.o
 OBJS  += aescrypt.o aeskey.o aestab.o
 
 all: tests test-openssl
diff --git a/README b/README
index c3f8ee40dd..feb8d0adb2 100644
--- a/README
+++ b/README
@@ -7,6 +7,7 @@ These include:
 - AES/Rijndael encryption/decryption
 - Big Number (256 bit) Arithmetics
 - BIP32 Hierarchical Deterministic Wallets
+- BIP39 Mnemonic code
 - ECDSA signing/verifying (only hardcoded secp256k1 curve,
   uses RFC6979 for deterministic signatures)
 - ECDSA public key derivation + Base58 address representation
diff --git a/bip39.c b/bip39.c
new file mode 100644
index 0000000000..f8eb4d4037
--- /dev/null
+++ b/bip39.c
@@ -0,0 +1,155 @@
+#include <string.h>
+
+#include "bip39.h"
+#include "sha2.h"
+#include "aes.h"
+#include "bip39_english.h"
+
+#define RIJNDAEL_ITERATIONS 10000
+
+void mnemonic_rijndael(uint8_t *data, int len, char *passphrase, bool encrypt)
+{
+	if (len != 16 && len != 24 && len != 32) return;
+
+	SHA256_CTX sha_ctx;
+	aes_ctx ctx;
+	uint8_t key[32];
+	int i;
+
+	SHA256_Init(&sha_ctx);
+	SHA256_Update(&sha_ctx, (uint8_t *)"mnemonic", 8);
+	if (passphrase) {
+		SHA256_Update(&sha_ctx, (uint8_t *)passphrase, strlen(passphrase));
+	}
+	SHA256_Final(key, &sha_ctx);
+
+	aes_blk_len(len, &ctx);
+
+	if (encrypt) {
+		aes_enc_key(key, 32, &ctx);
+		for (i = 0; i < RIJNDAEL_ITERATIONS; i++) {
+			aes_enc_blk(data, data, &ctx);
+		}
+	} else {
+		aes_dec_key(key, 32, &ctx);
+		for (i = 0; i < RIJNDAEL_ITERATIONS; i++) {
+			aes_dec_blk(data, data, &ctx);
+		}
+	}
+}
+
+#define mnemonic_stretch(D, L, P) mnemonic_rijndael((D), (L), (P), true)
+#define mnemonic_unstretch(D, L, P) mnemonic_rijndael((D), (L), (P), false)
+
+static char mnemo[24 * 10];
+static char bits[256 + 8];
+
+char mnemonic_checksum(uint8_t *data, int len)
+{
+	char r = 0;
+	int i;
+	switch (len) {
+		case 16:	// checksum = 4 bits
+			for (i = 0; i < 16; i++) {
+				r ^= (data[i] & 0xF0) >> 4;
+				r ^= (data[i] & 0x0F);
+			}
+			break;
+		case 24:	// checksum = 6 bits
+			for (i = 0; i < 8; i++) {
+				r ^= (data[3 * i] & 0xFC) >> 2;						// xxxxxx__ ________ ________
+				r ^= ((data[3 * i] & 0x03) << 4) | ((data[3 * i + 1] & 0xF0) >> 4);	// ______xx xxxx____ ________
+				r ^= ((data[3 * i + 1] & 0x0F) << 2) | ((data[3 * i + 2] & 0xC0) >> 6);	// ________ ____xxxx xx______
+				r ^= data[3 * i + 2] & 0x3F;						// ________ ________ __xxxxxx
+			}
+			break;
+		case 32:	// checksum = 8 bits
+			for (i = 0; i < 32; i++) {
+				r ^= data[i];
+			}
+			break;
+	}
+	return r;
+}
+
+const char *mnemonic_encode(uint8_t *data, int len, char *passphrase)
+{
+	if (len != 16 && len != 24 && len != 32) return 0;
+
+	mnemonic_stretch(data, len, passphrase);
+
+	int i, j;
+	for (i = 0; i < len; i++) {
+		for (j = 0; j < 8; j++) {
+			bits[8 * i + j] = (data[i] & (1 << (7 - j))) > 0;
+		}
+	}
+
+	char checksum = mnemonic_checksum(data, len);
+	for (j = 0; j < (len/4); j++) {
+		bits[8 * len + j] = (checksum & (1 << ((len / 4 - 1) - j))) > 0;
+	}
+
+	len = len * 3 / 4;
+	char *p = mnemo;
+	for (i = 0; i < len; i++) {
+		int idx = 0;
+		for (j = 0; j < 11; j++) {
+			idx += bits[i * 11 + j] << (10 - j);
+		}
+		strcpy(p, wordlist[idx]);
+		p += strlen(wordlist[idx]);
+		*p = (i < len - 1) ? ' ' : 0;
+		p++;
+	}
+
+	return mnemo;
+}
+
+int wordlist_index(const char *word)
+{
+	int i = 0;
+	while (wordlist[i]) {
+		if (strcmp(word, wordlist[i]) == 0) return i;
+		i++;
+	}
+	return -1;
+}
+
+int mnemonic_decode(const char *mnemonic, uint8_t *data, char *passphrase)
+{
+	strcpy(mnemo, mnemonic);
+
+	int i, j, b = 0, len;
+	char *p = strtok(mnemo, " ");
+	while (p) {
+		int idx = wordlist_index(p);
+		if (idx < 0 || idx > 2047) return 0;
+		for (j = 0; j < 11; j++) {
+			bits[b] = (idx & (1 << (10 - j))) > 0;
+			b++;
+		}
+		p = strtok(NULL, " ");
+	}
+	if (b != 128 + 4 && b != 192 + 6 && b != 256 + 8) return 0;
+
+	len = b / 33 * 4;
+
+	for (i = 0; i < len; i++) {
+		data[i] = 0;
+		for (j = 0; j < 8; j++) {
+			data[i] |= bits[8 * i + j] << (7 - j);
+		}
+	}
+	char checksum = 0;
+	for (j = 0; j < (len/4); j++) {
+		checksum |= bits[8 * len + j] << ((len / 4 - 1) - j);
+	}
+	if (checksum != mnemonic_checksum(data, len)) {
+		return 0;
+	}
+
+	mnemonic_unstretch(data, len, passphrase);
+
+	return len;
+}
diff --git a/bip39.h b/bip39.h
new file mode 100644
index 0000000000..34fbf62fcd
--- /dev/null
+++ b/bip39.h
@@ -0,0 +1,11 @@
+#ifndef __BIP39_H__
+#define __BIP39_H__
+
+#include <stdbool.h>
+#include <stdint.h>
+
+const char *mnemonic_encode(uint8_t *data, int len, char *passphrase);
+
+int mnemonic_decode(const char *mnemonic, uint8_t *data, char *passphrase);
+
+#endif
diff --git a/bip39_english.h b/bip39_english.h
new file mode 100644
index 0000000000..d9c1734727
--- /dev/null
+++ b/bip39_english.h
@@ -0,0 +1,2051 @@
+const char *wordlist[] = {
+"abandon",
+"ability",
+"able",
+"about",
+"above",
+"absent",
+"absorb",
+"abstract",
+"absurd",
+"abuse",
+"access",
+"accident",
+"account",
+"accuse",
+"achieve",
+"acid",
+"acoustic",
+"acquire",
+"across",
+"act",
+"action",
+"actor",
+"actress",
+"actual",
+"adapt",
+"add",
+"addict",
+"address",
+"adjust",
+"admit",
+"adult",
+"advance",
+"advice",
+"aerobic",
+"affair",
+"afford",
+"afraid",
+"again",
+"age",
+"agent",
+"agree",
+"ahead",
+"aim",
+"air",
+"airport",
+"aisle",
+"alarm",
+"album",
+"alcohol",
+"alert",
+"alien",
+"all",
+"alley",
+"allow",
+"almost",
+"alone",
+"alpha",
+"already",
+"also",
+"alter",
+"always",
+"amateur",
+"amazing",
+"among",
+"amount",
+"amused",
+"analyst",
+"anchor",
+"ancient",
+"anger",
+"angle",
+"angry",
+"animal",
+"ankle",
+"announce",
+"annual",
+"another",
+"answer",
+"antenna",
+"antique",
+"anxiety",
+"any",
+"apart",
+"apology",
+"appear",
+"apple",
+"approve",
+"april",
+"arch",
+"arctic",
+"area",
+"arena",
+"argue",
+"arm",
+"armed",
+"armor",
+"army",
+"around",
+"arrange",
+"arrest",
+"arrive",
+"arrow",
+"art",
+"artefact",
+"artist",
+"artwork",
+"ask",
+"aspect",
+"assault",
+"asset",
+"assist",
+"assume",
+"asthma",
+"athlete",
+"atom",
+"attack",
+"attend",
+"attitude",
+"attract",
+"auction",
+"audit",
+"august",
+"aunt",
+"author",
+"auto",
+"autumn",
+"average",
+"avocado",
+"avoid",
+"awake",
+"aware",
+"away",
+"awesome",
+"awful",
+"awkward",
+"axis",
+"baby",
+"bachelor",
+"bacon",
+"badge",
+"bag",
+"balance",
+"balcony",
+"ball",
+"bamboo",
+"banana",
+"banner",
+"bar",
+"barely",
+"bargain",
+"barrel",
+"base",
+"basic",
+"basket",
+"battle",
+"beach",
+"bean",
+"beauty",
+"because",
+"become",
+"beef",
+"before",
+"begin",
+"behave",
+"behind",
+"believe",
+"below",
+"belt",
+"bench",
+"benefit",
+"best",
+"betray",
+"better",
+"between",
+"beyond",
+"bicycle",
+"bid",
+"bike",
+"bind",
+"biology",
+"bird",
+"birth",
+"bitter",
+"black",
+"blade",
+"blame",
+"blanket",
+"blast",
+"bleak",
+"bless",
+"blind",
+"blood",
+"blossom",
+"blouse",
+"blue",
+"blur",
+"blush",
+"board",
+"boat",
+"body",
+"boil",
+"bomb",
+"bone",
+"bonus",
+"book",
+"boost",
+"border",
+"boring",
+"borrow",
+"boss",
+"bottom",
+"bounce",
+"box",
+"boy",
+"bracket",
+"brain",
+"brand",
+"brass",
+"brave",
+"bread",
+"breeze",
+"brick",
+"bridge",
+"brief",
+"bright",
+"bring",
+"brisk",
+"broccoli",
+"broken",
+"bronze",
+"broom",
+"brother",
+"brown",
+"brush",
+"bubble",
+"buddy",
+"budget",
+"buffalo",
+"build",
+"bulb",
+"bulk",
+"bullet",
+"bundle",
+"bunker",
+"burden",
+"burger",
+"burst",
+"bus",
+"business",
+"busy",
+"butter",
+"buyer",
+"buzz",
+"cabbage",
+"cabin",
+"cable",
+"cactus",
+"cage",
+"cake",
+"call",
+"calm",
+"camera",
+"camp",
+"can",
+"canal",
+"cancel",
+"candy",
+"cannon",
+"canoe",
+"canvas",
+"canyon",
+"capable",
+"capital",
+"captain",
+"car",
+"carbon",
+"card",
+"cargo",
+"carpet",
+"carry",
+"cart",
+"case",
+"cash",
+"casino",
+"castle",
+"casual",
+"cat",
+"catalog",
+"catch",
+"category",
+"cattle",
+"caught",
+"cause",
+"caution",
+"cave",
+"ceiling",
+"celery",
+"cement",
+"census",
+"century",
+"cereal",
+"certain",
+"chair",
+"chalk",
+"champion",
+"change",
+"chaos",
+"chapter",
+"charge",
+"chase",
+"chat",
+"cheap",
+"check",
+"cheese",
+"chef",
+"cherry",
+"chest",
+"chicken",
+"chief",
+"child",
+"chimney",
+"choice",
+"choose",
+"chronic",
+"chuckle",
+"chunk",
+"churn",
+"cigar",
+"cinnamon",
+"circle",
+"citizen",
+"city",
+"civil",
+"claim",
+"clap",
+"clarify",
+"claw",
+"clay",
+"clean",
+"clerk",
+"clever",
+"click",
+"client",
+"cliff",
+"climb",
+"clinic",
+"clip",
+"clock",
+"clog",
+"close",
+"cloth",
+"cloud",
+"clown",
+"club",
+"clump",
+"cluster",
+"clutch",
+"coach",
+"coast",
+"coconut",
+"code",
+"coffee",
+"coil",
+"coin",
+"collect",
+"color",
+"column",
+"combine",
+"come",
+"comfort",
+"comic",
+"common",
+"company",
+"concert",
+"conduct",
+"confirm",
+"congress",
+"connect",
+"consider",
+"control",
+"convince",
+"cook",
+"cool",
+"copper",
+"copy",
+"coral",
+"core",
+"corn",
+"correct",
+"cost",
+"cotton",
+"couch",
+"country",
+"couple",
+"course",
+"cousin",
+"cover",
+"coyote",
+"crack",
+"cradle",
+"craft",
+"cram",
+"crane",
+"crash",
+"crater",
+"crawl",
+"crazy",
+"cream",
+"credit",
+"creek",
+"crew",
+"cricket",
+"crime",
+"crisp",
+"critic",
+"crop",
+"cross",
+"crouch",
+"crowd",
+"crucial",
+"cruel",
+"cruise",
+"crumble",
+"crunch",
+"crush",
+"cry",
+"crystal",
+"cube",
+"culture",
+"cup",
+"cupboard",
+"curious",
+"current",
+"curtain",
+"curve",
+"cushion",
+"custom",
+"cute",
+"cycle",
+"dad",
+"damage",
+"damp",
+"dance",
+"danger",
+"daring",
+"dash",
+"daughter",
+"dawn",
+"day",
+"deal",
+"debate",
+"debris",
+"decade",
+"december",
+"decide",
+"decline",
+"decorate",
+"decrease",
+"deer",
+"defense",
+"define",
+"defy",
+"degree",
+"delay",
+"deliver",
+"demand",
+"demise",
+"denial",
+"dentist",
+"deny",
+"depart",
+"depend",
+"deposit",
+"depth",
+"deputy",
+"derive",
+"describe",
+"desert",
+"design",
+"desk",
+"despair",
+"destroy",
+"detail",
+"detect",
+"develop",
+"device",
+"devote",
+"diagram",
+"dial",
+"diamond",
+"diary",
+"dice",
+"diesel",
+"diet",
+"differ",
+"digital",
+"dignity",
+"dilemma",
+"dinner",
+"dinosaur",
+"direct",
+"dirt",
+"disagree",
+"discover",
+"disease",
+"dish",
+"dismiss",
+"disorder",
+"display",
+"distance",
+"divert",
+"divide",
+"divorce",
+"dizzy",
+"doctor",
+"document",
+"dog",
+"doll",
+"dolphin",
+"domain",
+"donate",
+"donkey",
+"donor",
+"door",
+"dose",
+"double",
+"dove",
+"draft",
+"dragon",
+"drama",
+"drastic",
+"draw",
+"dream",
+"dress",
+"drift",
+"drill",
+"drink",
+"drip",
+"drive",
+"drop",
+"drum",
+"dry",
+"duck",
+"dumb",
+"dune",
+"during",
+"dust",
+"dutch",
+"duty",
+"dwarf",
+"dynamic",
+"eager",
+"eagle",
+"early",
+"earn",
+"earth",
+"easily",
+"east",
+"easy",
+"echo",
+"ecology",
+"economy",
+"edge",
+"edit",
+"educate",
+"effort",
+"egg",
+"eight",
+"either",
+"elbow",
+"elder",
+"electric",
+"elegant",
+"element",
+"elephant",
+"elevator",
+"elite",
+"else",
+"embark",
+"embody",
+"embrace",
+"emerge",
+"emotion",
+"employ",
+"empower",
+"empty",
+"enable",
+"enact",
+"end",
+"endless",
+"endorse",
+"enemy",
+"energy",
+"enforce",
+"engage",
+"engine",
+"enhance",
+"enjoy",
+"enlist",
+"enough",
+"enrich",
+"enroll",
+"ensure",
+"enter",
+"entire",
+"entry",
+"envelope",
+"episode",
+"equal",
+"equip",
+"era",
+"erase",
+"erode",
+"erosion",
+"error",
+"erupt",
+"escape",
+"essay",
+"essence",
+"estate",
+"eternal",
+"ethics",
+"evidence",
+"evil",
+"evoke",
+"evolve",
+"exact",
+"example",
+"excess",
+"exchange",
+"excite",
+"exclude",
+"excuse",
+"execute",
+"exercise",
+"exhaust",
+"exhibit",
+"exile",
+"exist",
+"exit",
+"exotic",
+"expand",
+"expect",
+"expire",
+"explain",
+"expose",
+"express",
+"extend",
+"extra",
+"eye",
+"eyebrow",
+"fabric",
+"face",
+"faculty",
+"fade",
+"faint",
+"faith",
+"fall",
+"false",
+"fame",
+"family",
+"famous",
+"fan",
+"fancy",
+"fantasy",
+"farm",
+"fashion",
+"fat",
+"fatal",
+"father",
+"fatigue",
+"fault",
+"favorite",
+"feature",
+"february",
+"federal",
+"fee",
+"feed",
+"feel",
+"female",
+"fence",
+"festival",
+"fetch",
+"fever",
+"few",
+"fiber",
+"fiction",
+"field",
+"figure",
+"file",
+"film",
+"filter",
+"final",
+"find",
+"fine",
+"finger",
+"finish",
+"fire",
+"firm",
+"first",
+"fiscal",
+"fish",
+"fit",
+"fitness",
+"fix",
+"flag",
+"flame",
+"flash",
+"flat",
+"flavor",
+"flee",
+"flight",
+"flip",
+"float",
+"flock",
+"floor",
+"flower",
+"fluid",
+"flush",
+"fly",
+"foam",
+"focus",
+"fog",
+"foil",
+"fold",
+"follow",
+"food",
+"foot",
+"force",
+"forest",
+"forget",
+"fork",
+"fortune",
+"forum",
+"forward",
+"fossil",
+"foster",
+"found",
+"fox",
+"fragile",
+"frame",
+"frequent",
+"fresh",
+"friend",
+"fringe",
+"frog",
+"front",
+"frost",
+"frown",
+"frozen",
+"fruit",
+"fuel",
+"fun",
+"funny",
+"furnace",
+"fury",
+"future",
+"gadget",
+"gain",
+"galaxy",
+"gallery",
+"game",
+"gap",
+"garage",
+"garbage",
+"garden",
+"garlic",
+"garment",
+"gas",
+"gasp",
+"gate",
+"gather",
+"gauge",
+"gaze",
+"general",
+"genius",
+"genre",
+"gentle",
+"genuine",
+"gesture",
+"ghost",
+"giant",
+"gift",
+"giggle",
+"ginger",
+"giraffe",
+"girl",
+"give",
+"glad",
+"glance",
+"glare",
+"glass",
+"glide",
+"glimpse",
+"globe",
+"gloom",
+"glory",
+"glove",
+"glow",
+"glue",
+"goat",
+"goddess",
+"gold",
+"good",
+"goose",
+"gorilla",
+"gospel",
+"gossip",
+"govern",
+"gown",
+"grab",
+"grace",
+"grain",
+"grant",
+"grape",
+"grass",
+"gravity",
+"great",
+"green",
+"grid",
+"grief",
+"grit",
+"grocery",
+"group",
+"grow",
+"grunt",
+"guard",
+"guess",
+"guide",
+"guilt",
+"guitar",
+"gun",
+"gym",
+"habit",
+"hair",
+"half",
+"hammer",
+"hamster",
+"hand",
+"happy",
+"harbor",
+"hard",
+"harsh",
+"harvest",
+"hat",
+"have",
+"hawk",
+"hazard",
+"head",
+"health",
+"heart",
+"heavy",
+"hedgehog",
+"height",
+"hello",
+"helmet",
+"help",
+"hen",
+"hero",
+"hidden",
+"high",
+"hill",
+"hint",
+"hip",
+"hire",
+"history",
+"hobby",
+"hockey",
+"hold",
+"hole",
+"holiday",
+"hollow",
+"home",
+"honey",
+"hood",
+"hope",
+"horn",
+"horror",
+"horse",
+"hospital",
+"host",
+"hotel",
+"hour",
+"hover",
+"hub",
+"huge",
+"human",
+"humble",
+"humor",
+"hundred",
+"hungry",
+"hunt",
+"hurdle",
+"hurry",
+"hurt",
+"husband",
+"hybrid",
+"ice",
+"icon",
+"idea",
+"identify",
+"idle",
+"ignore",
+"ill",
+"illegal",
+"illness",
+"image",
+"imitate",
+"immense",
+"immune",
+"impact",
+"impose",
+"improve",
+"impulse",
+"inch",
+"include",
+"income",
+"increase",
+"index",
+"indicate",
+"indoor",
+"industry",
+"infant",
+"inflict",
+"inform",
+"inhale",
+"inherit",
+"initial",
+"inject",
+"injury",
+"inmate",
+"inner",
+"innocent",
+"input",
+"inquiry",
+"insane",
+"insect",
+"inside",
+"inspire",
+"install",
+"intact",
+"interest",
+"into",
+"invest",
+"invite",
+"involve",
+"iron",
+"island",
+"isolate",
+"issue",
+"item",
+"ivory",
+"jacket",
+"jaguar",
+"jar",
+"jazz",
+"jealous",
+"jeans",
+"jelly",
+"jewel",
+"job",
+"join",
+"joke",
+"journey",
+"joy",
+"judge",
+"juice",
+"jump",
+"jungle",
+"junior",
+"junk",
+"just",
+"kangaroo",
+"keen",
+"keep",
+"ketchup",
+"key",
+"kick",
+"kid",
+"kidney",
+"kind",
+"kingdom",
+"kiss",
+"kit",
+"kitchen",
+"kite",
+"kitten",
+"kiwi",
+"knee",
+"knife",
+"knock",
+"know",
+"lab",
+"label",
+"labor",
+"ladder",
+"lady",
+"lake",
+"lamp",
+"language",
+"laptop",
+"large",
+"later",
+"latin",
+"laugh",
+"laundry",
+"lava",
+"law",
+"lawn",
+"lawsuit",
+"layer",
+"lazy",
+"leader",
+"leaf",
+"learn",
+"leave",
+"lecture",
+"left",
+"leg",
+"legal",
+"legend",
+"leisure",
+"lemon",
+"lend",
+"length",
+"lens",
+"leopard",
+"lesson",
+"letter",
+"level",
+"liar",
+"liberty",
+"library",
+"license",
+"life",
+"lift",
+"light",
+"like",
+"limb",
+"limit",
+"link",
+"lion",
+"liquid",
+"list",
+"little",
+"live",
+"lizard",
+"load",
+"loan",
+"lobster",
+"local",
+"lock",
+"logic",
+"lonely",
+"long",
+"loop",
+"lottery",
+"loud",
+"lounge",
+"love",
+"loyal",
+"lucky",
+"luggage",
+"lumber",
+"lunar",
+"lunch",
+"luxury",
+"lyrics",
+"machine",
+"mad",
+"magic",
+"magnet",
+"maid",
+"mail",
+"main",
+"major",
+"make",
+"mammal",
+"man",
+"manage",
+"mandate",
+"mango",
+"mansion",
+"manual",
+"maple",
+"marble",
+"march",
+"margin",
+"marine",
+"market",
+"marriage",
+"mask",
+"mass",
+"master",
+"match",
+"material",
+"math",
+"matrix",
+"matter",
+"maximum",
+"maze",
+"meadow",
+"mean",
+"measure",
+"meat",
+"mechanic",
+"medal",
+"media",
+"melody",
+"melt",
+"member",
+"memory",
+"mention",
+"menu",
+"mercy",
+"merge",
+"merit",
+"merry",
+"mesh",
+"message",
+"metal",
+"method",
+"middle",
+"midnight",
+"milk",
+"million",
+"mimic",
+"mind",
+"minimum",
+"minor",
+"minute",
+"miracle",
+"mirror",
+"misery",
+"miss",
+"mistake",
+"mix",
+"mixed",
+"mixture",
+"mobile",
+"model",
+"modify",
+"mom",
+"moment",
+"monitor",
+"monkey",
+"monster",
+"month",
+"moon",
+"moral",
+"more",
+"morning",
+"mosquito",
+"mother",
+"motion",
+"motor",
+"mountain",
+"mouse",
+"move",
+"movie",
+"much",
+"muffin",
+"mule",
+"multiply",
+"muscle",
+"museum",
+"mushroom",
+"music",
+"must",
+"mutual",
+"myself",
+"mystery",
+"myth",
+"naive",
+"name",
+"napkin",
+"narrow",
+"nasty",
+"nation",
+"nature",
+"near",
+"neck",
+"need",
+"negative",
+"neglect",
+"neither",
+"nephew",
+"nerve",
+"nest",
+"net",
+"network",
+"neutral",
+"never",
+"news",
+"next",
+"nice",
+"night",
+"noble",
+"noise",
+"nominee",
+"noodle",
+"normal",
+"north",
+"nose",
+"notable",
+"note",
+"nothing",
+"notice",
+"novel",
+"now",
+"nuclear",
+"number",
+"nurse",
+"nut",
+"oak",
+"obey",
+"object",
+"oblige",
+"obscure",
+"observe",
+"obtain",
+"obvious",
+"occur",
+"ocean",
+"october",
+"odor",
+"off",
+"offer",
+"office",
+"often",
+"oil",
+"okay",
+"old",
+"olive",
+"olympic",
+"omit",
+"once",
+"one",
+"onion",
+"online",
+"only",
+"open",
+"opera",
+"opinion",
+"oppose",
+"option",
+"orange",
+"orbit",
+"orchard",
+"order",
+"ordinary",
+"organ",
+"orient",
+"original",
+"orphan",
+"ostrich",
+"other",
+"outdoor",
+"outer",
+"output",
+"outside",
+"oval",
+"oven",
+"over",
+"own",
+"owner",
+"oxygen",
+"oyster",
+"ozone",
+"pact",
+"paddle",
+"page",
+"pair",
+"palace",
+"palm",
+"panda",
+"panel",
+"panic",
+"panther",
+"paper",
+"parade",
+"parent",
+"park",
+"parrot",
+"party",
+"pass",
+"patch",
+"path",
+"patient",
+"patrol",
+"pattern",
+"pause",
+"pave",
+"payment",
+"peace",
+"peanut",
+"pear",
+"peasant",
+"pelican",
+"pen",
+"penalty",
+"pencil",
+"people",
+"pepper",
+"perfect",
+"permit",
+"person",
+"pet",
+"phone",
+"photo",
+"phrase",
+"physical",
+"piano",
+"picnic",
+"picture",
+"piece",
+"pig",
+"pigeon",
+"pill",
+"pilot",
+"pink",
+"pioneer",
+"pipe",
+"pistol",
+"pitch",
+"pizza",
+"place",
+"planet",
+"plastic",
+"plate",
+"play",
+"please",
+"pledge",
+"pluck",
+"plug",
+"plunge",
+"poem",
+"poet",
+"point",
+"polar",
+"pole",
+"police",
+"pond",
+"pony",
+"pool",
+"popular",
+"portion",
+"position",
+"possible",
+"post",
+"potato",
+"pottery",
+"poverty",
+"powder",
+"power",
+"practice",
+"praise",
+"predict",
+"prefer",
+"prepare",
+"present",
+"pretty",
+"prevent",
+"price",
+"pride",
+"primary",
+"print",
+"priority",
+"prison",
+"private",
+"prize",
+"problem",
+"process",
+"produce",
+"profit",
+"program",
+"project",
+"promote",
+"proof",
+"property",
+"prosper",
+"protect",
+"proud",
+"provide",
+"public",
+"pudding",
+"pull",
+"pulp",
+"pulse",
+"pumpkin",
+"punch",
+"pupil",
+"puppy",
+"purchase",
+"purity",
+"purpose",
+"purse",
+"push",
+"put",
+"puzzle",
+"pyramid",
+"quality",
+"quantum",
+"quarter",
+"question",
+"quick",
+"quit",
+"quiz",
+"quote",
+"rabbit",
+"raccoon",
+"race",
+"rack",
+"radar",
+"radio",
+"rail",
+"rain",
+"raise",
+"rally",
+"ramp",
+"ranch",
+"random",
+"range",
+"rapid",
+"rare",
+"rate",
+"rather",
+"raven",
+"raw",
+"razor",
+"ready",
+"real",
+"reason",
+"rebel",
+"rebuild",
+"recall",
+"receive",
+"recipe",
+"record",
+"recycle",
+"reduce",
+"reflect",
+"reform",
+"refuse",
+"region",
+"regret",
+"regular",
+"reject",
+"relax",
+"release",
+"relief",
+"rely",
+"remain",
+"remember",
+"remind",
+"remove",
+"render",
+"renew",
+"rent",
+"reopen",
+"repair",
+"repeat",
+"replace",
+"report",
+"require",
+"rescue",
+"resemble",
+"resist",
+"resource",
+"response",
+"result",
+"retire",
+"retreat",
+"return",
+"reunion",
+"reveal",
+"review",
+"reward",
+"rhythm",
+"rib",
+"ribbon",
+"rice",
+"rich",
+"ride",
+"ridge",
+"rifle",
+"right",
+"rigid",
+"ring",
+"riot",
+"ripple",
+"risk",
+"ritual",
+"rival",
+"river",
+"road",
+"roast",
+"robot",
+"robust",
+"rocket",
+"romance",
+"roof",
+"rookie",
+"room",
+"rose",
+"rotate",
+"rough",
+"round",
+"route",
+"royal",
+"rubber",
+"rude",
+"rug",
+"rule",
+"run",
+"runway",
+"rural",
+"sad",
+"saddle",
+"sadness",
+"safe",
+"sail",
+"salad",
+"salmon",
+"salon",
+"salt",
+"salute",
+"same",
+"sample",
+"sand",
+"satisfy",
+"satoshi",
+"sauce",
+"sausage",
+"save",
+"say",
+"scale",
+"scan",
+"scare",
+"scatter",
+"scene",
+"scheme",
+"school",
+"science",
+"scissors",
+"scorpion",
+"scout",
+"scrap",
+"screen",
+"script",
+"scrub",
+"sea",
+"search",
+"season",
+"seat",
+"second",
+"secret",
+"section",
+"security",
+"seed",
+"seek",
+"segment",
+"select",
+"sell",
+"seminar",
+"senior",
+"sense",
+"sentence",
+"series",
+"service",
+"session",
+"settle",
+"setup",
+"seven",
+"shadow",
+"shaft",
+"shallow",
+"share",
+"shed",
+"shell",
+"sheriff",
+"shield",
+"shift",
+"shine",
+"ship",
+"shiver",
+"shock",
+"shoe",
+"shoot",
+"shop",
+"short",
+"shoulder",
+"shove",
+"shrimp",
+"shrug",
+"shuffle",
+"shy",
+"sibling",
+"sick",
+"side",
+"siege",
+"sight",
+"sign",
+"silent",
+"silk",
+"silly",
+"silver",
+"similar",
+"simple",
+"since",
+"sing",
+"siren",
+"sister",
+"situate",
+"six",
+"size",
+"skate",
+"sketch",
+"ski",
+"skill",
+"skin",
+"skirt",
+"skull",
+"slab",
+"slam",
+"sleep",
+"slender",
+"slice",
+"slide",
+"slight",
+"slim",
+"slogan",
+"slot",
+"slow",
+"slush",
+"small",
+"smart",
+"smile",
+"smoke",
+"smooth",
+"snack",
+"snake",
+"snap",
+"sniff",
+"snow",
+"soap",
+"soccer",
+"social",
+"sock",
+"soda",
+"soft",
+"solar",
+"soldier",
+"solid",
+"solution",
+"solve",
+"someone",
+"song",
+"soon",
+"sorry",
+"sort",
+"soul",
+"sound",
+"soup",
+"source",
+"south",
+"space",
+"spare",
+"spatial",
+"spawn",
+"speak",
+"special",
+"speed",
+"spell",
+"spend",
+"sphere",
+"spice",
+"spider",
+"spike",
+"spin",
+"spirit",
+"split",
+"spoil",
+"sponsor",
+"spoon",
+"sport",
+"spot",
+"spray",
+"spread",
+"spring",
+"spy",
+"square",
+"squeeze",
+"squirrel",
+"stable",
+"stadium",
+"staff",
+"stage",
+"stairs",
+"stamp",
+"stand",
+"start",
+"state",
+"stay",
+"steak",
+"steel",
+"stem",
+"step",
+"stereo",
+"stick",
+"still",
+"sting",
+"stock",
+"stomach",
+"stone",
+"stool",
+"story",
+"stove",
+"strategy",
+"street",
+"strike",
+"strong",
+"struggle",
+"student",
+"stuff",
+"stumble",
+"style",
+"subject",
+"submit",
+"subway",
+"success",
+"such",
+"sudden",
+"suffer",
+"sugar",
+"suggest",
+"suit",
+"summer",
+"sun",
+"sunny",
+"sunset",
+"super",
+"supply",
+"supreme",
+"sure",
+"surface",
+"surge",
+"surprise",
+"surround",
+"survey",
+"suspect",
+"sustain",
+"swallow",
+"swamp",
+"swap",
+"swarm",
+"swear",
+"sweet",
+"swift",
+"swim",
+"swing",
+"switch",
+"sword",
+"symbol",
+"symptom",
+"syrup",
+"system",
+"table",
+"tackle",
+"tag",
+"tail",
+"talent",
+"talk",
+"tank",
+"tape",
+"target",
+"task",
+"taste",
+"tattoo",
+"taxi",
+"teach",
+"team",
+"tell",
+"ten",
+"tenant",
+"tennis",
+"tent",
+"term",
+"test",
+"text",
+"thank",
+"that",
+"theme",
+"then",
+"theory",
+"there",
+"they",
+"thing",
+"this",
+"thought",
+"three",
+"thrive",
+"throw",
+"thumb",
+"thunder",
+"ticket",
+"tide",
+"tiger",
+"tilt",
+"timber",
+"time",
+"tiny",
+"tip",
+"tired",
+"tissue",
+"title",
+"toast",
+"tobacco",
+"today",
+"toddler",
+"toe",
+"together",
+"toilet",
+"token",
+"tomato",
+"tomorrow",
+"tone",
+"tongue",
+"tonight",
+"tool",
+"tooth",
+"top",
+"topic",
+"topple",
+"torch",
+"tornado",
+"tortoise",
+"toss",
+"total",
+"tourist",
+"toward",
+"tower",
+"town",
+"toy",
+"track",
+"trade",
+"traffic",
+"tragic",
+"train",
+"transfer",
+"trap",
+"trash",
+"travel",
+"tray",
+"treat",
+"tree",
+"trend",
+"trial",
+"tribe",
+"trick",
+"trigger",
+"trim",
+"trip",
+"trophy",
+"trouble",
+"truck",
+"true",
+"truly",
+"trumpet",
+"trust",
+"truth",
+"try",
+"tube",
+"tuition",
+"tumble",
+"tuna",
+"tunnel",
+"turkey",
+"turn",
+"turtle",
+"twelve",
+"twenty",
+"twice",
+"twin",
+"twist",
+"two",
+"type",
+"typical",
+"ugly",
+"umbrella",
+"unable",
+"unaware",
+"uncle",
+"uncover",
+"under",
+"undo",
+"unfair",
+"unfold",
+"unhappy",
+"uniform",
+"unique",
+"unit",
+"universe",
+"unknown",
+"unlock",
+"until",
+"unusual",
+"unveil",
+"update",
+"upgrade",
+"uphold",
+"upon",
+"upper",
+"upset",
+"urban",
+"urge",
+"usage",
+"use",
+"used",
+"useful",
+"useless",
+"usual",
+"utility",
+"vacant",
+"vacuum",
+"vague",
+"valid",
+"valley",
+"valve",
+"van",
+"vanish",
+"vapor",
+"various",
+"vast",
+"vault",
+"vehicle",
+"velvet",
+"vendor",
+"venture",
+"venue",
+"verb",
+"verify",
+"version",
+"very",
+"vessel",
+"veteran",
+"viable",
+"vibrant",
+"vicious",
+"victory",
+"video",
+"view",
+"village",
+"vintage",
+"violin",
+"virtual",
+"virus",
+"visa",
+"visit",
+"visual",
+"vital",
+"vivid",
+"vocal",
+"voice",
+"void",
+"volcano",
+"volume",
+"vote",
+"voyage",
+"wage",
+"wagon",
+"wait",
+"walk",
+"wall",
+"walnut",
+"want",
+"warfare",
+"warm",
+"warrior",
+"wash",
+"wasp",
+"waste",
+"water",
+"wave",
+"way",
+"wealth",
+"weapon",
+"wear",
+"weasel",
+"weather",
+"web",
+"wedding",
+"weekend",
+"weird",
+"welcome",
+"west",
+"wet",
+"whale",
+"what",
+"wheat",
+"wheel",
+"when",
+"where",
+"whip",
+"whisper",
+"wide",
+"width",
+"wife",
+"wild",
+"will",
+"win",
+"window",
+"wine",
+"wing",
+"wink",
+"winner",
+"winter",
+"wire",
+"wisdom",
+"wise",
+"wish",
+"witness",
+"wolf",
+"woman",
+"wonder",
+"wood",
+"wool",
+"word",
+"work",
+"world",
+"worry",
+"worth",
+"wrap",
+"wreck",
+"wrestle",
+"wrist",
+"write",
+"wrong",
+"yard",
+"year",
+"yellow",
+"you",
+"young",
+"youth",
+"zebra",
+"zero",
+"zone",
+"zoo",
+0,
+};
diff --git a/tests.c b/tests.c
index dd80ca823c..7df7603b99 100644
--- a/tests.c
+++ b/tests.c
@@ -29,6 +29,7 @@
 #include "aes.h"
 #include "bignum.h"
 #include "bip32.h"
+#include "bip39.h"
 #include "ecdsa.h"
 #include "sha2.h"
 
@@ -290,6 +291,87 @@ START_TEST(test_rijndael)
 }
 END_TEST
 
+START_TEST(test_mnemonic)
+{
+	static const char *vectors[] = {
+		"00000000000000000000000000000000",
+		"risk tiger venture dinner age assume float denial penalty hello game wing",
+		"7f7f7f7f7f7f7f7f7f7f7f7f7f7f7f7f",
+		"truth chase learn pretty right casual acoustic frozen betray main slogan method",
+		"80808080808080808080808080808080",
+		"olive garment twenty drill people finish hat own usual level milk usage",
+		"ffffffffffffffffffffffffffffffff",
+		"laundry faint system client frog vanish plug shell slot cable large embrace",
+		"000000000000000000000000000000000000000000000000",
+		"giant twelve seat embark ostrich jazz leader lunch budget hover much weapon vendor build truth garden year list",
+		"7f7f7f7f7f7f7f7f7f7f7f7f7f7f7f7f7f7f7f7f7f7f7f7f",
+		"awful faint gun mean fuel side slogan marine glad donkey velvet oyster movie real type digital dress federal",
+		"808080808080808080808080808080808080808080808080",
+		"bless carpet daughter animal hospital pave faculty escape fortune song sign twin unknown bread mobile normal agent use",
+		"ffffffffffffffffffffffffffffffffffffffffffffffff",
+		"saddle curve flight drama client resemble venture arch will ordinary enrich clutch razor shallow trophy tumble dice outer",
+		"0000000000000000000000000000000000000000000000000000000000000000",
+		"supreme army trim onion neglect coach squirrel spider device glass cabbage giant web digital floor able social magnet only fork fuel embrace salt fence",
+		"7f7f7f7f7f7f7f7f7f7f7f7f7f7f7f7f7f7f7f7f7f7f7f7f7f7f7f7f7f7f7f7f",
+		"cloth video uncle switch year captain artist country adjust edit inherit ocean tennis soda baby express hospital forest panel actual profit boy spice elite",
+		"8080808080808080808080808080808080808080808080808080808080808080",
+		"fence twin prize extra choose mask twist deny cereal quarter can power term ostrich leg staff nature nut swift sausage amateur aim script wisdom",
+		"ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff",
+		"moon fiscal evidence exile rifle series neglect giant exclude banana glance frown kangaroo globe turtle hat fitness casual sudden select idle arctic best unlock",
+		"449ea2d7249c6e0d8d295424fb8894cf",
+		"choice barrel artefact cram increase sell veteran matrix mirror hollow walk pave",
+		"75fc3f44a7ff8e2b8af05aa18bded3827a3796df406763dd",
+		"crack outside teach chat praise client manual scorpion predict chalk decrease casino lunch garbage enable ball when bamboo",
+		"1cce2f8c2c6a7f2d8473ebf1c32ce13b36737835d7a8768f44dcf96d64782c0e",
+		"muffin evoke all fiber night guard black quote neck expire dial tenant leisure have dragon neck notable peace captain insane nice uphold shine angry",
+		"3daa82dd08bd144ec9fb9f77c6ece3d2",
+		"foil dawn net enroll turtle bird vault trumpet service fun immune unveil",
+		"9720239c0039f8446d44334daec325f3c24b3a490315d6d9",
+		"damp all desert dash insane pear debate easily soup enough goddess make friend plug violin pact wealth insect",
+		"fe58c6644bc3fad95832d4400cea0cce208c8b19bb4734a26995440b7fae7600",
+		"wet sniff asthma once gap enrich pumpkin define trust rude gesture keen grass fine emerge census immense smooth ritual spirit rescue problem beef choice",
+		"99fe82c94edadffe75e1cc64cbd7ada7",
+		"thing real emerge verify domain cloud lens teach travel radio effort glad",
+		"4fd6e8d06d55b4700130f8f462f7f9bfc6188da83e3faadb",
+		"diary opinion lobster code orange odor insane permit spirit evolve upset final antique grant friend dutch say enroll",
+		"7a547fb59606e89ba88188013712946f6cb31c3e0ca606a7ee1ff23f57272c63",
+		"layer owner legal stadium glance oyster element spell episode eager wagon stand pride old defense black print junior fade easy topic ready galaxy debris",
+		"e5fc62d20e0e5d9b2756e8d4d91cbb80",
+		"flat make unit discover rifle armed unit acquire group panel nerve want",
+		"d29be791a9e4b6a48ff79003dbf31d6afabdc4290a273765",
+		"absurd valve party disorder basket injury make blanket vintage ancient please random theory cart retire odor borrow belt",
+		"c87c135433c16f1ecbf9919dc53dd9f30f85824dc7264d4e1bd644826c902be2",
+		"upper will wisdom term once bean blur inquiry used bamboo frequent hamster amazing cake attack any author mimic leopard day token joy install company",
+		0,
+		0,
+	};
+
+	const char **d, **s, *m;
+
+	// check encode
+	d = vectors;
+	s = vectors + 1;
+	while (*d && *s) {
+		m = mnemonic_encode(fromhex(*d), strlen(*d) / 2, 0);
+		ck_assert_ptr_ne(m, 0);
+		ck_assert_str_eq(m, *s);
+		d += 2; s += 2;
+	}
+
+	// check decode
+	d = vectors;
+	s = vectors + 1;
+	uint8_t data[32];
+	int len;
+	while (*d && *s) {
+		len = mnemonic_decode(*s, data, 0);
+		ck_assert_int_eq(len, strlen(*d) / 2);
+		ck_assert_mem_eq(fromhex(*d), data, len);
+		d += 2; s += 2;
+	}
+}
+END_TEST
+
 // define test suite and cases
 Suite *test_suite(void)
 {
@@ -314,6 +396,10 @@ Suite *test_suite(void)
 	tcase_add_test(tc, test_rijndael);
 	suite_add_tcase(s, tc);
 
+	tc = tcase_create("bip39");
+	tcase_add_test(tc, test_mnemonic);
+	suite_add_tcase(s, tc);
+
 	return s;
 }