diff --git a/LICENSE b/LICENSE
index 9e52d9b..74cee2b 100644
--- a/LICENSE
+++ b/LICENSE
@@ -1,4 +1,4 @@
-Copyright (C) 2016 Marius Schellenberger
+Copyright (C) 2025 Marius Schellenberger
 All rights reserved.
 
 Redistribution and use in source and binary forms, with or without
diff --git a/README.md b/README.md
index ad89f76..74aa8a3 100644
--- a/README.md
+++ b/README.md
@@ -1 +1,61 @@
-# jwt - a simple JSON Web Token library in Go
+# jwt - a simple JSON Web Token library written in Go
+
+## Usage
+
+```
+package main
+
+import (
+	"fmt"
+	"git.giftfish.de/ston1th/jwt"
+	"log"
+	"time"
+)
+
+func main() {
+	// create a new signing instance
+	JWT, err := jwt.New(time.Hour, jwt.NewMemBlacklist(), nil)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	// create a new token
+	t := jwt.NewToken(jwt.Claims{
+		"username": "admin",
+	}, nil)
+
+	// sign the token
+	err = JWT.Sign(t)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	// print the token string
+	token := t.String()
+	fmt.Println(token)
+
+	// decode the token string
+	newToken, err := jwt.DecodeToken(token)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	// verify the decoded token
+	err = JWT.Verify(newToken)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	// add the token to the blacklist
+	err = JWT.Invalidate(newToken)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	// try to verify the blacklisted token, it should fail
+	err = JWT.Verify(newToken)
+	if err != nil {
+		log.Fatal(err)
+	}
+}
+```
diff --git a/blacklist.go b/blacklist.go
new file mode 100644
index 0000000..180c5fd
--- /dev/null
+++ b/blacklist.go
@@ -0,0 +1,63 @@
+// Copyright (C) 2025 Marius Schellenberger
+
+package jwt
+
+import "sync"
+
+// Blacklist is the blacklisting storage interface
+type Blacklist interface {
+	Add(string, int64) error
+	Remove(string) error
+	Check(string) bool
+	Map() (BlacklistMap, error)
+}
+
+// BlacklistMap is the blacklist map structure
+type BlacklistMap map[string]int64
+
+// MemBlacklist implements the Blacklist interface
+type MemBlacklist struct {
+	// protects list
+	sync.RWMutex
+	list BlacklistMap
+}
+
+// NewMemBlacklist implements the Blacklist interface using an in-memory map
+func NewMemBlacklist() *MemBlacklist {
+	return &MemBlacklist{list: make(BlacklistMap)}
+}
+
+// Add adds a new token signature with expiration time to the blacklist
+func (mb *MemBlacklist) Add(sig string, exp int64) error {
+	mb.Lock()
+	mb.list[sig] = exp
+	mb.Unlock()
+	return nil
+}
+
+// Remove deletes a token signature from the blacklist
+func (mb *MemBlacklist) Remove(sig string) error {
+	mb.Lock()
+	delete(mb.list, sig)
+	mb.Unlock()
+	return nil
+}
+
+// Check returns true if a token signature is blacklisted and false otherwise
+func (mb *MemBlacklist) Check(sig string) (ok bool) {
+	mb.RLock()
+	_, ok = mb.list[sig]
+	mb.RUnlock()
+	return
+}
+
+// Map returns the blacklist in the form of a iterable map structure for cleanup
+func (mb *MemBlacklist) Map() (list BlacklistMap, err error) {
+	list = make(BlacklistMap)
+	mb.RLock()
+	for k, v := range mb.list {
+		list[k] = v
+	}
+	mb.RUnlock()
+	return
+}
diff --git a/claims.go b/claims.go
new file mode 100644
index 0000000..a5f4364
--- /dev/null
+++ b/claims.go
@@ -0,0 +1,78 @@
+// Copyright (C) 2025 Marius Schellenberger
+
+package jwt
+
+// Claims is the claim type of the token
+// The Claims map is not goroutine safe
+type Claims map[string]interface{}
+
+// Get returns a value from the claims map
+func (c Claims) Get(key string) (v interface{}, ok bool) {
+	v, ok = c[key]
+	return
+}
+
+// GetString returns a string from the claims map
+func (c Claims) GetString(key string) (s string) {
+	if v, ok := c.Get(key); ok && v != nil {
+		s, _ = v.(string)
+	}
+	return
+}
+
+// GetBool returns a bool from the claims map
+func (c Claims) GetBool(key string) (b bool) {
+	if v, ok := c.Get(key); ok && v != nil {
+		b, _ = v.(bool)
+	}
+	return
+}
+
+// GetInt returns an int from the claims map
+func (c Claims) GetInt(key string) (i int) {
+	i = int(c.GetInt64(key))
+	return
+}
+
+// GetInt64 returns an int64 from the claims map
+func (c Claims) GetInt64(key string) (i int64) {
+	if v, ok := c.Get(key); ok && v != nil {
+		switch val := v.(type) {
+		case int64:
+			i = val
+		case float64:
+			i = int64(val)
+		}
+	}
+	return
+}
+
+// getFloat64 returns a float64 and ok from the claims map
+func (c Claims) GetFloat64(key string) (f float64) {
+	if v, ok := c.Get(key); ok && v != nil {
+		f, _ = v.(float64)
+	}
+	return
+}
+
+// Set sets the value of key in the claims map, if not nil
+func (c Claims) Set(key string, v interface{}) {
+	if c == nil {
+		return
+	}
+	c[key] = v
+}
+
+// Delete removes the key from the claims map
+func (c Claims) Delete(key string) {
+	delete(c, key)
+}
+
+// Copy returns a new Claims map
+func (c Claims) Copy() (n Claims) {
+	n = make(Claims)
+	for k, v := range c {
+		n[k] = v
+	}
+	return
+}
diff --git a/encoding.go b/encoding.go
new file mode 100644
index 0000000..3693f5f
--- /dev/null
+++ b/encoding.go
@@ -0,0 +1,7 @@
+// Copyright (C) 2025 Marius Schellenberger
+
+package jwt
+
+import "encoding/base64"
+
+var enc = base64.RawURLEncoding
diff --git a/go.mod b/go.mod
new file mode 100644
index 0000000..6752b42
--- /dev/null
+++ b/go.mod
@@ -0,0 +1 @@
+module git.giftfish.de/ston1th/jwt/v3
diff --git a/hash.go b/hash.go
new file mode 100644
index 0000000..e47c0cc
--- /dev/null
+++ b/hash.go
@@ -0,0 +1,79 @@
+// Copyright (C) 2025 Marius Schellenberger
+
+package jwt
+
+import (
+	"crypto/sha256"
+	"crypto/sha512"
+	"hash"
+)
+
+const (
+	HS256Name = "HS256"
+	HS384Name = "HS384"
+	HS512Name = "HS512"
+)
+
+// NewHash returns the Hash type equal to the input string
+func NewHash(alg string) Hash {
+	switch alg {
+	case HS256Name:
+		return hs256
+	case HS384Name:
+		return hs384
+	case HS512Name:
+		return hs512
+	}
+	return nil
+}
+
+var (
+	hs256 = HS256{}
+	hs384 = HS384{}
+	hs512 = HS512{}
+)
+
+// Hash is the hashsum interface for signing the jwt
+type Hash interface {
+	Hash() hash.Hash
+	Alg() string
+}
+
+// HS256 implements the Hash interface with SHA256
+type HS256 struct{}
+
+// Alg returns the algorithm name "HS256"
+func (HS256) Alg() string {
+	return HS256Name
+}
+
+// Hash returns a new hash.Hash instance of the SHA256 algorithm
+func (HS256) Hash() hash.Hash {
+	return sha256.New()
+}
+
+// HS384 implements the Hash interface with SHA384
+type HS384 struct{}
+
+// Alg returns the algorithm name "HS384"
+func (HS384) Alg() string {
+	return HS384Name
+}
+
+// Hash returns a new hash.Hash instance of the SHA384 algorithm
+func (HS384) Hash() hash.Hash {
+	return sha512.New384()
+}
+
+// HS512 implements the Hash interface with SHA512
+type HS512 struct{}
+
+// Alg returns the algorithm name "HS512"
+func (HS512) Alg() string {
+	return HS512Name
+}
+
+// Hash returns a new hash.Hash instance of the SHA512 algorithm
+func (HS512) Hash() hash.Hash {
+	return sha512.New()
+}
diff --git a/jwt.go b/jwt.go
index 03c545c..f9ce6af 100644
--- a/jwt.go
+++ b/jwt.go
@@ -1,118 +1,141 @@
+// Copyright (C) 2025 Marius Schellenberger
+
 // Package jwt provides a easy to use JSON Web Token and blacklisting library
 package jwt
 
 import (
 	"crypto/hmac"
 	"crypto/rand"
-	"crypto/sha256"
-	"crypto/sha512"
-	"encoding/base64"
 	"encoding/json"
 	"errors"
-	"hash"
-	"strings"
+	"io"
 	"sync"
 	"time"
 )
 
 const (
-	// Header is the default HTTP Authorization header name
-	Header = "Authorization"
+	// HTTPHeader is the default HTTP Authorization header name
+	HTTPHeader = "Authorization"
 	// DefaultExpiry is the default token expiration time
 	DefaultExpiry = time.Hour * 12
-	typ           = "JWT"
-	keySize       = 64
+	// KeySize is the secret key size
+	KeySize = 64
+
+	// Typ is the JWT type
+	Typ = "JWT"
+	// TypClaim is the typ claim name
+	TypClaim = "typ"
+	// AlgClaim is the alg claim name
+	AlgClaim = "alg"
+	// ExpClaim is the exp claim name
+	ExpClaim = "exp"
+	// NbfClaim is the nbf claim name
+	NbfClaim = "nbf"
+	// NonceClaim
+	NonceClaim = "nonce"
+	// TokenSeparator is the tokens separator char
+	TokenSeparator = "."
 )
 
-// Hash represents the three diffrernt hash types
-type Hash int
+// DefaultSecretReader is the default secret key generator
+var DefaultSecretReader = rand.Reader
 
-const (
-	HS256 Hash = iota //SHA256
-	HS384             //SHA384
-	HS512             //SHA512
-	unsupported
-)
-
-// String returns the string representation of Hash
-func (h Hash) String() string {
-	switch h {
-	case HS256:
-		return "HS256"
-	case HS384:
-		return "HS384"
-	case HS512:
-		return "HS512"
-	}
-	return ""
-}
+const jwtErr = "jwt: "
 
 var (
-	ErrNoJWT               = errors.New("no json web token")
-	ErrUnsupportedAlg      = errors.New("unsupported algoritm")
-	ErrInvalid             = errors.New("token validation failed")
-	ErrBlacklisted         = errors.New("token blacklisted")
-	ErrBlacklistNotEnabled = errors.New("blacklisting is not enabled")
-	ErrNBF                 = errors.New("token not valid yet")
-	ErrEXP                 = errors.New("token expired")
-	ErrMissingEXP          = errors.New("missing exp claim")
-	ErrMissingTokenParts   = errors.New("missíng token parts")
-	ErrEmptySignature      = errors.New("token signature is empty")
+	ErrNoJWT               = errors.New(jwtErr + "not a json web token")
+	ErrEmptyToken          = errors.New(jwtErr + "token is empty")
+	ErrUnsupportedAlg      = errors.New(jwtErr + "unsupported algorithm")
+	ErrInvalid             = errors.New(jwtErr + "token validation failed")
+	ErrBlacklisted         = errors.New(jwtErr + "token blacklisted")
+	ErrBlacklistNotEnabled = errors.New(jwtErr + "blacklisting is not enabled")
+	ErrNbf                 = errors.New(jwtErr + "token not valid yet")
+	ErrExp                 = errors.New(jwtErr + "token expired")
+	ErrMissingNbf          = errors.New(jwtErr + "missing nbf claim")
+	ErrMissingExp          = errors.New(jwtErr + "missing exp claim")
+	ErrMissingTokenParts   = errors.New(jwtErr + "missing token parts")
+	ErrEmptySignature      = errors.New(jwtErr + "token signature is empty")
+	ErrTokenIsNil          = errors.New(jwtErr + "token is nil")
+	ErrInvalidKeySize      = errors.New(jwtErr + "invalid secret key size")
 )
 
-// parseHash returns the hash.Hash type equal to the input string
-func parseHash(alg string) (h func() hash.Hash) {
-	switch alg {
-	case "HS256":
-		h = sha256.New
-	case "HS384":
-		h = sha512.New384
-	case "HS512":
-		h = sha512.New
+type JWTOption func(*JWT)
+
+func WithExpiry(expiry time.Duration) JWTOption {
+	return func(jwt *JWT) {
+		jwt.expiry = expiry
+	}
+}
+
+func WithBlacklist(blacklist Blacklist) JWTOption {
+	return func(jwt *JWT) {
+		jwt.blacklist = blacklist
+	}
+}
+func WithSecret(secret io.Reader) JWTOption {
+	return func(jwt *JWT) {
+		jwt.secretReader = secret
+	}
+}
+func WithNonce() JWTOption {
+	return func(jwt *JWT) {
+		jwt.nonce = true
 	}
-	return
 }
 
 // JWT represents the JSON Web Token signing and blacklisting infrastructure
 type JWT struct {
-	key    []byte
-	expiry time.Duration
-
-	// protects list
-	sync.RWMutex
-	blacklist bool
-	list      map[string]int64
-	stop      chan struct{}
+	secretReader io.Reader
+	key          []byte
+	expiry       time.Duration
+	blacklist    Blacklist
+	nonce        bool
+	stopOnce     sync.Once
+	done         chan struct{}
 }
 
 // New returns a new JWT object with the given expiry timeout.
 // If the timeout is less or equal to zero the default expiry (12 hours) is used.
+// The secret key size needs to be at least 64 bytes.
+// If secret is nil the DefaultSecretReader is used.
 // If blacklisting is enabled, the JWT object leaks a goroutine to garbage-collect expired blacklisted tokens.
 // Call the Stop() method to exit the goroutine.
-func New(expiry time.Duration, blacklist bool) (*JWT, error) {
-	if expiry <= 0 {
-		expiry = DefaultExpiry
+func New(options ...JWTOption) (*JWT, error) {
+	jwt := &JWT{}
+	for _, option := range options {
+		option(jwt)
 	}
-	key := make([]byte, keySize)
-	_, err := rand.Read(key)
+	if jwt.expiry <= 0 {
+		jwt.expiry = DefaultExpiry
+	}
+	if jwt.secretReader == nil {
+		jwt.secretReader = DefaultSecretReader
+	}
+	secret := io.LimitReader(jwt.secretReader, KeySize)
+	key := make([]byte, KeySize)
+	i, err := secret.Read(key)
 	if err != nil {
-		return nil, err
+		return nil, errors.New(jwtErr + "secret reader error: " + err.Error())
 	}
-	jwt := &JWT{
-		key:       key,
-		expiry:    expiry,
-		blacklist: blacklist,
+	if i < KeySize {
+		return nil, ErrInvalidKeySize
 	}
-	if blacklist {
-		jwt.list = make(map[string]int64)
-		jwt.stop = make(chan struct{})
+	jwt.key = key
+	if jwt.blacklist != nil {
+		jwt.done = make(chan struct{})
 		go jwt.clean()
 	}
 	return jwt, nil
 }
 
-func (jwt *JWT) sum(token string, h func() hash.Hash) []byte {
-	mac := hmac.New(h, jwt.key)
+// Expiry returns the configured expiry
+func (jwt *JWT) Expiry() time.Duration {
+	return jwt.expiry
+}
+
+// sum calculates the HMAC hash sum of the token
+func (jwt *JWT) sum(token string, h Hash) []byte {
+	mac := hmac.New(h.Hash, jwt.key)
 	mac.Write([]byte(token))
 	return mac.Sum(nil)
 }
@@ -120,33 +143,33 @@ func (jwt *JWT) sum(token string, h func() hash.Hash) []byte {
 // Invalidate checks if a token is already blacklisted
 // If the token is not blacklisted, it will get blacklisted
 func (jwt *JWT) Invalidate(t *Token) error {
-	if !jwt.blacklist {
+	if jwt.blacklist == nil {
 		return ErrBlacklistNotEnabled
 	}
-	var (
-		expOK bool
-		exp   int64
-	)
-	switch n := t.Claims["exp"].(type) {
-	case json.Number:
-		if i, err := n.Int64(); err == nil {
-			exp = i
-			expOK = true
-		}
-	case float64:
-		exp = int64(n)
-		expOK = true
+	if t == nil {
+		return ErrTokenIsNil
 	}
-	if !expOK {
-		return ErrMissingEXP
-	}
-	if err := jwt.blacklisted(t.Signature); err != nil {
+	if err := jwt.blacklisted(t.Sig()); err != nil {
 		return err
 	}
-	jwt.Lock()
-	defer jwt.Unlock()
-	jwt.list[t.Signature] = exp
-	return nil
+	if t.Header.GetString(TypClaim) != Typ {
+		return ErrNoJWT
+	}
+	h := NewHash(t.Header.GetString(AlgClaim))
+	if h == nil {
+		return ErrUnsupportedAlg
+	}
+	exp := t.Claims.GetInt64(ExpClaim)
+	switch {
+	case exp == 0:
+		return ErrMissingExp
+	case Now() > exp:
+		return ErrExp
+	}
+	if !hmac.Equal(jwt.sum(t.Data(), h), t.RawSig()) {
+		return ErrInvalid
+	}
+	return jwt.blacklist.Add(t.Sig(), exp)
 }
 
 // blacklisted checks if a token is blacklisted
@@ -154,193 +177,120 @@ func (jwt *JWT) blacklisted(sig string) error {
 	if sig == "" {
 		return ErrEmptySignature
 	}
-	jwt.RLock()
-	defer jwt.RUnlock()
-	_, ok := jwt.list[sig]
-	if ok {
+	if jwt.blacklist.Check(sig) {
 		return ErrBlacklisted
 	}
 	return nil
 }
 
-// clean will look for expired blacklisted tokens and removes them
+// clean looks for expired blacklisted tokens and removes them
 func (jwt *JWT) clean() {
 	for {
 		t := time.NewTimer(time.Hour)
 		select {
 		case <-t.C:
-		case <-jwt.stop:
+		case <-jwt.done:
 			t.Stop()
 			return
 		}
-		now := time.Now().UTC().Unix()
-		jwt.Lock()
-		defer jwt.Unlock()
-		for k, v := range jwt.list {
+		now := Now()
+		m, err := jwt.blacklist.Map()
+		if err != nil {
+			continue
+		}
+		for k, v := range m {
 			if now > v {
-				delete(jwt.list, k)
+				jwt.blacklist.Remove(k)
 			}
 		}
 	}
 }
 
 // Sign will sign the provided token using the secret key
-// This will overwrite existing 'exp' and 'nbf' claims
+// If the 'exp' and 'nbf' claims do not exist, they will be written to the default values in UNIX format:
+// 'exp': Now + expiry specified at New() or DefaultExpiry (UTC)
+// 'nbf': Now (UTC)
 func (jwt *JWT) Sign(t *Token) (err error) {
-	now := time.Now().UTC()
-	t.Claims["exp"] = now.Add(jwt.expiry).Unix()
-	t.Claims["nbf"] = now.Unix()
-	h, err := json.Marshal(t.Header)
-	if err != nil {
-		return
+	if t == nil {
+		return ErrTokenIsNil
 	}
-	c, err := json.Marshal(t.Claims)
-	if err != nil {
-		return
+	if t.Header.GetString(TypClaim) != Typ {
+		return ErrNoJWT
 	}
-	var hf func() hash.Hash
-	switch a := t.Header["alg"].(type) {
-	case string:
-		hf = parseHash(a)
-		if hf == nil {
-			return ErrUnsupportedAlg
-		}
-	default:
+	h := NewHash(t.Header.GetString(AlgClaim))
+	if h == nil {
 		return ErrUnsupportedAlg
 	}
-	t.Data = strings.Join([]string{base64.URLEncoding.EncodeToString(h), base64.URLEncoding.EncodeToString(c)}, ".")
-	t.Raw = strings.Join([]string{t.Data, base64.URLEncoding.EncodeToString(jwt.sum(t.Data, hf))}, ".")
+	now := time.Now()
+	if _, ok := t.Claims.Get(ExpClaim); !ok {
+		t.Claims.Set(ExpClaim, newExp(now, jwt.expiry))
+	}
+	if _, ok := t.Claims.Get(NbfClaim); !ok {
+		t.Claims.Set(NbfClaim, NewNbf(now))
+	}
+	if jwt.nonce {
+		t.Claims.Set(NonceClaim, enc.EncodeToString(key16()))
+	}
+	head, err := json.Marshal(t.Header)
+	if err != nil {
+		return
+	}
+	claims, err := json.Marshal(t.Claims)
+	if err != nil {
+		return
+	}
+	t.data = enc.EncodeToString(head) + TokenSeparator + enc.EncodeToString(claims)
+	t.rawSignature = jwt.sum(t.data, h)
+	t.signature = enc.EncodeToString(t.rawSignature)
+	t.raw = t.data + TokenSeparator + t.signature
 	return
 }
 
 // Verify will verify the provided token using the secret key
 func (jwt *JWT) Verify(t *Token) error {
-	now := time.Now().UTC().Unix()
-	var (
-		exp   int64
-		nbf   int64
-		expOK bool
-		nbfOK bool
-		hf    func() hash.Hash
-	)
-	switch t := t.Header["typ"].(type) {
-	case string:
-		if t != typ {
-			return ErrNoJWT
-		}
-	default:
-		return ErrNoJWT
+	if t == nil {
+		return ErrTokenIsNil
 	}
-	switch a := t.Header["alg"].(type) {
-	case string:
-		hf = parseHash(a)
-		if hf == nil {
-			return ErrUnsupportedAlg
-		}
-	default:
-		return ErrUnsupportedAlg
-	}
-
-	switch n := t.Claims["exp"].(type) {
-	case json.Number:
-		if i, err := n.Int64(); err == nil {
-			exp = i
-			expOK = true
-		}
-	case float64:
-		exp = int64(n)
-		expOK = true
-	}
-	switch n := t.Claims["nbf"].(type) {
-	case json.Number:
-		if i, err := n.Int64(); err == nil {
-			nbf = i
-			nbfOK = true
-		}
-	case float64:
-		nbf = int64(n)
-		nbfOK = true
-	}
-	if expOK && jwt.blacklist {
-		err := jwt.blacklisted(t.Signature)
-		if err != nil {
+	if jwt.blacklist != nil {
+		if err := jwt.blacklisted(t.Sig()); err != nil {
 			return err
 		}
 	}
-	if expOK && now > exp {
-		return ErrEXP
+	now := Now()
+	if t.Header.GetString(TypClaim) != Typ {
+		return ErrNoJWT
 	}
-	if nbfOK && now < nbf {
-		return ErrNBF
+	h := NewHash(t.Header.GetString(AlgClaim))
+	if h == nil {
+		return ErrUnsupportedAlg
 	}
-	if !hmac.Equal(jwt.sum(t.Data, hf), t.RawSignature) {
+	exp := t.Claims.GetInt64(ExpClaim)
+	switch {
+	case exp == 0:
+		return ErrMissingExp
+	case now > exp:
+		return ErrExp
+	}
+	nbf := t.Claims.GetInt64(NbfClaim)
+	switch {
+	case nbf == 0:
+		return ErrMissingNbf
+	case now < nbf:
+		return ErrNbf
+	}
+	if !hmac.Equal(jwt.sum(t.Data(), h), t.RawSig()) {
 		return ErrInvalid
 	}
 	return nil
 }
 
-// Stop will end the cleaner goroutinge execution
-// Calling Stop twice or more will panic
+// Stop will end the cleaner goroutine execution
 func (jwt *JWT) Stop() error {
-	if !jwt.blacklist {
+	if jwt.blacklist == nil {
 		return ErrBlacklistNotEnabled
 	}
-	select {
-	case jwt.stop <- struct{}{}:
-		close(jwt.stop)
-	default:
-	}
+	jwt.stopOnce.Do(func() {
+		close(jwt.done)
+	})
 	return nil
 }
-
-// DecodeToken decodes a raw string token into a *Token object
-func DecodeToken(token string) (t *Token, err error) {
-	parts := strings.Split(token, ".")
-	if len(parts) < 3 {
-		return nil, ErrMissingTokenParts
-	}
-	t = new(Token)
-	header, err := base64.URLEncoding.DecodeString(parts[0])
-	if err != nil {
-		return
-	}
-	err = json.Unmarshal(header, &t.Header)
-	if err != nil {
-		return
-	}
-	claims, err := base64.URLEncoding.DecodeString(parts[1])
-	if err != nil {
-		return
-	}
-	err = json.Unmarshal(claims, &t.Claims)
-	if err != nil {
-		return
-	}
-	t.RawSignature, err = base64.URLEncoding.DecodeString(parts[2])
-	t.Signature = parts[2]
-	t.Data = strings.Join(parts[:2], ".")
-	t.Raw = token
-	return
-}
-
-// Token is the JWT token representation
-type Token struct {
-	Raw          string
-	Data         string
-	Signature    string
-	RawSignature []byte
-	Exp          int64
-	Header       map[string]interface{}
-	Claims       map[string]interface{}
-}
-
-// NewToken returns a new *Token using the provided hash algorithm and claims
-func NewToken(hash Hash, claims map[string]interface{}) *Token {
-	return &Token{
-		Header: map[string]interface{}{
-			"alg": hash.String(),
-			"typ": typ,
-		},
-		Claims: claims,
-	}
-}
diff --git a/jwt_test.go b/jwt_test.go
index 0d04ad5..664cf8a 100644
--- a/jwt_test.go
+++ b/jwt_test.go
@@ -1,25 +1,250 @@
+// Copyright (C) 2025 Marius Schellenberger
+
 package jwt
 
 import (
+	"bytes"
+	"errors"
 	"testing"
 	"time"
 )
 
-func TestValidate(t *testing.T) {
-	jwt, _ := New(0, true)
-	token := NewToken(HS256, map[string]interface{}{
-		"sub":   "1234567890",
-		"name":  "John Doe",
-		"admin": true,
-		"fizz":  "buzz",
-	})
-	err := jwt.Sign(token)
-	t.Log(err, token)
-	nt, err := DecodeToken(token.Raw)
-	t.Log(nt, err)
-	time.Sleep(time.Second)
-	t.Log(jwt.Verify(nt))
-	jwt.Invalidate(nt)
-	t.Log(jwt.Verify(nt))
-	jwt.Stop()
+var claims = Claims{
+	"sub":   "1234567890",
+	"name":  "John Doe",
+	"admin": true,
+	"fizz":  "buzz",
+}
+
+func TestValidate(t *testing.T) {
+	jwt, err := New(
+		WithExpiry(time.Second),
+		WithBlacklist(NewMemBlacklist()),
+	)
+	if err != nil {
+		t.Error(err)
+	}
+	token := NewToken(claims.Copy(), nil)
+	err = jwt.Sign(token)
+	if err != nil {
+		t.Error(err)
+	}
+	_, err = DecodeToken("")
+	if err == nil {
+		t.Error(errors.New("token is empty"))
+	}
+	nt, err := DecodeToken(token.String())
+	if err != nil {
+		t.Error(err)
+	}
+	err = jwt.Verify(nt)
+	if err != nil {
+		t.Error(err)
+	}
+	time.Sleep(time.Second * 2)
+	err = jwt.Verify(nt)
+	if err == nil {
+		t.Error(errors.New("token should be expired"))
+	}
+
+	err = jwt.Invalidate(nt)
+	if err == nil {
+		t.Error(errors.New("token is expired"))
+	}
+
+	nt.Claims.Delete(ExpClaim)
+	err = jwt.Sign(nt)
+	if err != nil {
+		t.Error(err)
+	}
+	err = jwt.Verify(nt)
+	if err != nil {
+		t.Error(err)
+	}
+
+	err = jwt.Invalidate(nt)
+	if err != nil {
+		t.Error(err)
+	}
+	err = jwt.Invalidate(nt)
+	if err == nil {
+		t.Error(errors.New("double invalidate"))
+	}
+
+	err = jwt.Verify(nt)
+	if err == nil {
+		t.Error(errors.New("token should be blacklisted"))
+	}
+	err = jwt.Stop()
+	if err != nil {
+		t.Error(err)
+	}
+	// should not panic
+	err = jwt.Stop()
+	if err != nil {
+		t.Error(err)
+	}
+}
+
+func TestNonce(t *testing.T) {
+	jwt, err := New(
+		WithExpiry(time.Second),
+		WithNonce(),
+	)
+	if err != nil {
+		t.Error(err)
+	}
+	token := NewToken(claims.Copy(), nil)
+	err = jwt.Sign(token)
+	if err != nil {
+		t.Error(err)
+	}
+	nt, err := DecodeToken(token.String())
+	if err != nil {
+		t.Error(err)
+	}
+	err = jwt.Verify(nt)
+	if err != nil {
+		t.Error(err)
+	}
+	nonce := nt.Claims.GetString(NonceClaim)
+	if nonce == "" {
+		t.Error(errors.New("nonce is empty"))
+	}
+}
+
+func TestNoBlacklist(t *testing.T) {
+	jwt, err := New(WithExpiry(time.Second))
+	if err != nil {
+		t.Error(err)
+	}
+	token := NewToken(claims.Copy(), nil)
+	err = jwt.Sign(token)
+	if err != nil {
+		t.Error(err)
+	}
+	_, err = DecodeToken("")
+	if err == nil {
+		t.Error(errors.New("token is empty"))
+	}
+	nt, err := DecodeToken(token.String())
+	if err != nil {
+		t.Error(err)
+	}
+	err = jwt.Verify(nt)
+	if err != nil {
+		t.Error(err)
+	}
+	time.Sleep(time.Second * 2)
+	err = jwt.Verify(nt)
+	if err == nil {
+		t.Error(errors.New("token should be expired"))
+	}
+
+	err = jwt.Invalidate(nt)
+	if err == nil {
+		t.Error(errors.New("blacklisting should be disabled"))
+	}
+}
+
+func TestEmptySecretReader(t *testing.T) {
+	_, err := New(
+		WithExpiry(time.Second),
+		WithSecret(new(bytes.Buffer)),
+	)
+	if err == nil {
+		t.Error(errors.New("error should be secret reader error"))
+	}
+}
+
+func TestInvalidSecretReader(t *testing.T) {
+	_, err := New(
+		WithExpiry(time.Second),
+		WithSecret(bytes.NewBufferString("123")),
+	)
+	if err != ErrInvalidKeySize {
+		t.Error(errors.New("error should be invalid key size"))
+	}
+}
+
+func BenchmarkDecodeToken(b *testing.B) {
+	jwt, _ := New()
+	t := NewToken(claims.Copy(), nil)
+	jwt.Sign(t)
+	token := t.String()
+	b.ReportAllocs()
+	for i := 0; i < b.N; i++ {
+		DecodeToken(token)
+	}
+}
+
+func BenchmarkNew(b *testing.B) {
+	b.ReportAllocs()
+	for i := 0; i < b.N; i++ {
+		New()
+	}
+}
+
+func BenchmarkNewWithBlacklist(b *testing.B) {
+	b.ReportAllocs()
+	for i := 0; i < b.N; i++ {
+		New(WithBlacklist(NewMemBlacklist()))
+	}
+}
+
+func BenchmarkSignHS256(b *testing.B) {
+	jwt, _ := New()
+	t := NewToken(claims.Copy(), nil)
+	b.ReportAllocs()
+	for i := 0; i < b.N; i++ {
+		jwt.Sign(t)
+	}
+}
+
+func BenchmarkSignHS384(b *testing.B) {
+	jwt, _ := New()
+	t := NewToken(claims.Copy(), NewHash(HS384Name))
+	b.ReportAllocs()
+	for i := 0; i < b.N; i++ {
+		jwt.Sign(t)
+	}
+}
+
+func BenchmarkSignHS512(b *testing.B) {
+	jwt, _ := New()
+	t := NewToken(claims.Copy(), NewHash(HS512Name))
+	b.ReportAllocs()
+	for i := 0; i < b.N; i++ {
+		jwt.Sign(t)
+	}
+}
+
+func BenchmarkVerifyHS256(b *testing.B) {
+	jwt, _ := New()
+	t := NewToken(claims.Copy(), nil)
+	jwt.Sign(t)
+	b.ReportAllocs()
+	for i := 0; i < b.N; i++ {
+		jwt.Verify(t)
+	}
+}
+
+func BenchmarkVerifyHS384(b *testing.B) {
+	jwt, _ := New()
+	t := NewToken(claims.Copy(), NewHash(HS384Name))
+	jwt.Sign(t)
+	b.ReportAllocs()
+	for i := 0; i < b.N; i++ {
+		jwt.Verify(t)
+	}
+}
+
+func BenchmarkVerifyHS512(b *testing.B) {
+	jwt, _ := New()
+	t := NewToken(claims.Copy(), NewHash(HS512Name))
+	jwt.Sign(t)
+	b.ReportAllocs()
+	for i := 0; i < b.N; i++ {
+		jwt.Verify(t)
+	}
 }
diff --git a/rand.go b/rand.go
new file mode 100644
index 0000000..bd1b191
--- /dev/null
+++ b/rand.go
@@ -0,0 +1,11 @@
+// Copyright (C) 2025 Marius Schellenberger
+
+package jwt
+
+import "crypto/rand"
+
+func key16() []byte {
+	b := make([]byte, 16)
+	rand.Read(b)
+	return b
+}
diff --git a/time.go b/time.go
new file mode 100644
index 0000000..77e151f
--- /dev/null
+++ b/time.go
@@ -0,0 +1,24 @@
+// Copyright (C) 2025 Marius Schellenberger
+
+package jwt
+
+import "time"
+
+// Now returns the current time in UTC Unix format
+func Now() int64 {
+	return NewNbf(time.Now())
+}
+
+// NewNbf returns a new 'not before' date
+func NewNbf(t time.Time) int64 {
+	return t.UTC().Unix()
+}
+
+// NewExp returns a new expiration date
+func NewExp(d time.Duration) int64 {
+	return newExp(time.Now(), d)
+}
+
+func newExp(t time.Time, d time.Duration) int64 {
+	return t.UTC().Add(d).Unix()
+}
diff --git a/token.go b/token.go
new file mode 100644
index 0000000..772415c
--- /dev/null
+++ b/token.go
@@ -0,0 +1,98 @@
+// Copyright (C) 2025 Marius Schellenberger
+
+package jwt
+
+import (
+	"encoding/json"
+	"strings"
+)
+
+// Token represents a JWT token
+type Token struct {
+	raw          string
+	data         string
+	signature    string
+	rawSignature []byte
+	Header       Claims
+	Claims       Claims
+}
+
+// String returns the tokens encoded string
+func (t *Token) String() string {
+	return t.raw
+}
+
+// Sig returns the tokens URLEncoded signature
+func (t *Token) Sig() string {
+	return t.signature
+}
+
+// RawSig returns the tokens raw signature
+func (t *Token) RawSig() []byte {
+	return t.rawSignature
+}
+
+// Data returns the first two URLEncoded token fields
+func (t *Token) Data() string {
+	return t.data
+}
+
+// NewToken returns a new *Token using the provided hash algorithm and claims
+// If claims is nil, an empty map is used
+// If hash is nil, HS256 is used
+func NewToken(claims Claims, hash Hash) *Token {
+	if claims == nil {
+		claims = make(Claims)
+	}
+	if hash == nil {
+		hash = NewHash(HS256Name)
+	}
+	return &Token{
+		Header: Claims{
+			AlgClaim: hash.Alg(),
+			TypClaim: Typ,
+		},
+		Claims: claims,
+	}
+}
+
+// DecodeToken decodes a raw string token into a *Token object
+func DecodeToken(token string) (t *Token, err error) {
+	if token == "" {
+		return nil, ErrEmptyToken
+	}
+	parts := strings.Split(token, TokenSeparator)
+	if len(parts) < 3 {
+		return nil, ErrMissingTokenParts
+	}
+	if len(parts) > 3 {
+		return nil, ErrNoJWT
+	}
+	for _, v := range parts {
+		if v == "" {
+			return nil, ErrNoJWT
+		}
+	}
+	t = new(Token)
+	header, err := enc.DecodeString(parts[0])
+	if err != nil {
+		return
+	}
+	err = json.Unmarshal(header, &t.Header)
+	if err != nil {
+		return
+	}
+	claims, err := enc.DecodeString(parts[1])
+	if err != nil {
+		return
+	}
+	err = json.Unmarshal(claims, &t.Claims)
+	if err != nil {
+		return
+	}
+	t.rawSignature, err = enc.DecodeString(parts[2])
+	t.signature = parts[2]
+	t.data = parts[0] + TokenSeparator + parts[1]
+	t.raw = token
+	return
+}