diff --git a/build-all.sh b/build-all.sh
index d630237..eb2e72d 100644
--- a/build-all.sh
+++ b/build-all.sh
@@ -56,6 +56,7 @@ build_gradle_module "spring-boot/startup"
 build_gradle_module "spring-boot/static"
 build_gradle_module "spring-boot/validation"
 build_gradle_module "spring-boot/profiles"
+build_gradle_module "spring-boot/password-encoding"
 build_gradle_module "spring-cloud/feign-with-spring-data-rest"
 build_gradle_module "spring-cloud/sleuth-downstream-service"
 build_gradle_module "spring-cloud/sleuth-upstream-service"
diff --git a/spring-boot/password-encoding/.gitignore b/spring-boot/password-encoding/.gitignore
new file mode 100644
index 0000000..6c01878
--- /dev/null
+++ b/spring-boot/password-encoding/.gitignore
@@ -0,0 +1,32 @@
+HELP.md
+.gradle
+build/
+!gradle/wrapper/gradle-wrapper.jar
+!**/src/main/**
+!**/src/test/**
+
+### STS ###
+.apt_generated
+.classpath
+.factorypath
+.project
+.settings
+.springBeans
+.sts4-cache
+
+### IntelliJ IDEA ###
+.idea
+*.iws
+*.iml
+*.ipr
+out/
+
+### NetBeans ###
+/nbproject/private/
+/nbbuild/
+/dist/
+/nbdist/
+/.nb-gradle/
+
+### VS Code ###
+.vscode/
diff --git a/spring-boot/password-encoding/build.gradle b/spring-boot/password-encoding/build.gradle
new file mode 100644
index 0000000..3a1e180
--- /dev/null
+++ b/spring-boot/password-encoding/build.gradle
@@ -0,0 +1,41 @@
+plugins {
+    id 'org.springframework.boot' version '2.2.2.RELEASE'
+    id 'io.spring.dependency-management' version '1.0.8.RELEASE'
+    id 'java'
+}
+
+group = 'io.reflectoring'
+version = '0.0.1-SNAPSHOT'
+description = 'password-encoding-spring-boot'
+sourceCompatibility = '11'
+
+
+repositories {
+    mavenCentral()
+}
+
+configurations {
+    compileOnly {
+        extendsFrom annotationProcessor
+    }
+}
+
+dependencies {
+    implementation 'org.springframework.boot:spring-boot-starter-security:2.2.4.RELEASE'
+    implementation 'org.springframework.boot:spring-boot-starter-web:2.2.4.RELEASE'
+    implementation 'org.springframework.boot:spring-boot-starter-data-jpa:2.2.4.RELEASE'
+    implementation 'com.h2database:h2:1.4.200'
+    implementation 'org.flywaydb:flyway-core:6.0.8'
+    implementation 'org.bouncycastle:bcprov-jdk15on:1.64'
+    implementation 'org.projectlombok:lombok:1.18.12'
+    annotationProcessor 'org.projectlombok:lombok'
+    annotationProcessor 'org.springframework.boot:spring-boot-configuration-processor'
+    implementation 'com.google.guava:guava:28.2-jre'
+    testImplementation 'org.springframework.boot:spring-boot-starter-test:2.2.4.RELEASE'
+    testImplementation 'org.springframework.security:spring-security-test:5.2.1.RELEASE'
+}
+
+
+test {
+    useJUnitPlatform()
+}
diff --git a/spring-boot/password-encoding/gradle/wrapper/gradle-wrapper.jar b/spring-boot/password-encoding/gradle/wrapper/gradle-wrapper.jar
new file mode 100644
index 0000000..cc4fdc2
Binary files /dev/null and b/spring-boot/password-encoding/gradle/wrapper/gradle-wrapper.jar differ
diff --git a/spring-boot/password-encoding/gradle/wrapper/gradle-wrapper.properties b/spring-boot/password-encoding/gradle/wrapper/gradle-wrapper.properties
new file mode 100644
index 0000000..9492014
--- /dev/null
+++ b/spring-boot/password-encoding/gradle/wrapper/gradle-wrapper.properties
@@ -0,0 +1,5 @@
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-6.0.1-bin.zip
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists
diff --git a/spring-boot/password-encoding/gradlew b/spring-boot/password-encoding/gradlew
new file mode 100644
index 0000000..2fe81a7
--- /dev/null
+++ b/spring-boot/password-encoding/gradlew
@@ -0,0 +1,183 @@
+#!/usr/bin/env sh
+
+#
+# Copyright 2015 the original author or authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+##############################################################################
+##
+##  Gradle start up script for UN*X
+##
+##############################################################################
+
+# Attempt to set APP_HOME
+# Resolve links: $0 may be a link
+PRG="$0"
+# Need this for relative symlinks.
+while [ -h "$PRG" ] ; do
+    ls=`ls -ld "$PRG"`
+    link=`expr "$ls" : '.*-> \(.*\)$'`
+    if expr "$link" : '/.*' > /dev/null; then
+        PRG="$link"
+    else
+        PRG=`dirname "$PRG"`"/$link"
+    fi
+done
+SAVED="`pwd`"
+cd "`dirname \"$PRG\"`/" >/dev/null
+APP_HOME="`pwd -P`"
+cd "$SAVED" >/dev/null
+
+APP_NAME="Gradle"
+APP_BASE_NAME=`basename "$0"`
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
+
+# Use the maximum available, or set MAX_FD != -1 to use that value.
+MAX_FD="maximum"
+
+warn () {
+    echo "$*"
+}
+
+die () {
+    echo
+    echo "$*"
+    echo
+    exit 1
+}
+
+# OS specific support (must be 'true' or 'false').
+cygwin=false
+msys=false
+darwin=false
+nonstop=false
+case "`uname`" in
+  CYGWIN* )
+    cygwin=true
+    ;;
+  Darwin* )
+    darwin=true
+    ;;
+  MINGW* )
+    msys=true
+    ;;
+  NONSTOP* )
+    nonstop=true
+    ;;
+esac
+
+CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
+
+# Determine the Java command to use to start the JVM.
+if [ -n "$JAVA_HOME" ] ; then
+    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+        # IBM's JDK on AIX uses strange locations for the executables
+        JAVACMD="$JAVA_HOME/jre/sh/java"
+    else
+        JAVACMD="$JAVA_HOME/bin/java"
+    fi
+    if [ ! -x "$JAVACMD" ] ; then
+        die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+    fi
+else
+    JAVACMD="java"
+    which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+fi
+
+# Increase the maximum file descriptors if we can.
+if [ "$cygwin" = "false" -a "$darwin" = "false" -a "$nonstop" = "false" ] ; then
+    MAX_FD_LIMIT=`ulimit -H -n`
+    if [ $? -eq 0 ] ; then
+        if [ "$MAX_FD" = "maximum" -o "$MAX_FD" = "max" ] ; then
+            MAX_FD="$MAX_FD_LIMIT"
+        fi
+        ulimit -n $MAX_FD
+        if [ $? -ne 0 ] ; then
+            warn "Could not set maximum file descriptor limit: $MAX_FD"
+        fi
+    else
+        warn "Could not query maximum file descriptor limit: $MAX_FD_LIMIT"
+    fi
+fi
+
+# For Darwin, add options to specify how the application appears in the dock
+if $darwin; then
+    GRADLE_OPTS="$GRADLE_OPTS \"-Xdock:name=$APP_NAME\" \"-Xdock:icon=$APP_HOME/media/gradle.icns\""
+fi
+
+# For Cygwin or MSYS, switch paths to Windows format before running java
+if [ "$cygwin" = "true" -o "$msys" = "true" ] ; then
+    APP_HOME=`cygpath --path --mixed "$APP_HOME"`
+    CLASSPATH=`cygpath --path --mixed "$CLASSPATH"`
+    JAVACMD=`cygpath --unix "$JAVACMD"`
+
+    # We build the pattern for arguments to be converted via cygpath
+    ROOTDIRSRAW=`find -L / -maxdepth 1 -mindepth 1 -type d 2>/dev/null`
+    SEP=""
+    for dir in $ROOTDIRSRAW ; do
+        ROOTDIRS="$ROOTDIRS$SEP$dir"
+        SEP="|"
+    done
+    OURCYGPATTERN="(^($ROOTDIRS))"
+    # Add a user-defined pattern to the cygpath arguments
+    if [ "$GRADLE_CYGPATTERN" != "" ] ; then
+        OURCYGPATTERN="$OURCYGPATTERN|($GRADLE_CYGPATTERN)"
+    fi
+    # Now convert the arguments - kludge to limit ourselves to /bin/sh
+    i=0
+    for arg in "$@" ; do
+        CHECK=`echo "$arg"|egrep -c "$OURCYGPATTERN" -`
+        CHECK2=`echo "$arg"|egrep -c "^-"`                                 ### Determine if an option
+
+        if [ $CHECK -ne 0 ] && [ $CHECK2 -eq 0 ] ; then                    ### Added a condition
+            eval `echo args$i`=`cygpath --path --ignore --mixed "$arg"`
+        else
+            eval `echo args$i`="\"$arg\""
+        fi
+        i=`expr $i + 1`
+    done
+    case $i in
+        0) set -- ;;
+        1) set -- "$args0" ;;
+        2) set -- "$args0" "$args1" ;;
+        3) set -- "$args0" "$args1" "$args2" ;;
+        4) set -- "$args0" "$args1" "$args2" "$args3" ;;
+        5) set -- "$args0" "$args1" "$args2" "$args3" "$args4" ;;
+        6) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" ;;
+        7) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" ;;
+        8) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" ;;
+        9) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" "$args8" ;;
+    esac
+fi
+
+# Escape application args
+save () {
+    for i do printf %s\\n "$i" | sed "s/'/'\\\\''/g;1s/^/'/;\$s/\$/' \\\\/" ; done
+    echo " "
+}
+APP_ARGS=`save "$@"`
+
+# Collect all arguments for the java command, following the shell quoting and substitution rules
+eval set -- $DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS "\"-Dorg.gradle.appname=$APP_BASE_NAME\"" -classpath "\"$CLASSPATH\"" org.gradle.wrapper.GradleWrapperMain "$APP_ARGS"
+
+exec "$JAVACMD" "$@"
diff --git a/spring-boot/password-encoding/gradlew.bat b/spring-boot/password-encoding/gradlew.bat
new file mode 100644
index 0000000..9618d8d
--- /dev/null
+++ b/spring-boot/password-encoding/gradlew.bat
@@ -0,0 +1,100 @@
+@rem
+@rem Copyright 2015 the original author or authors.
+@rem
+@rem Licensed under the Apache License, Version 2.0 (the "License");
+@rem you may not use this file except in compliance with the License.
+@rem You may obtain a copy of the License at
+@rem
+@rem      https://www.apache.org/licenses/LICENSE-2.0
+@rem
+@rem Unless required by applicable law or agreed to in writing, software
+@rem distributed under the License is distributed on an "AS IS" BASIS,
+@rem WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+@rem See the License for the specific language governing permissions and
+@rem limitations under the License.
+@rem
+
+@if "%DEBUG%" == "" @echo off
+@rem ##########################################################################
+@rem
+@rem  Gradle startup script for Windows
+@rem
+@rem ##########################################################################
+
+@rem Set local scope for the variables with windows NT shell
+if "%OS%"=="Windows_NT" setlocal
+
+set DIRNAME=%~dp0
+if "%DIRNAME%" == "" set DIRNAME=.
+set APP_BASE_NAME=%~n0
+set APP_HOME=%DIRNAME%
+
+@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+set DEFAULT_JVM_OPTS="-Xmx64m" "-Xms64m"
+
+@rem Find java.exe
+if defined JAVA_HOME goto findJavaFromJavaHome
+
+set JAVA_EXE=java.exe
+%JAVA_EXE% -version >NUL 2>&1
+if "%ERRORLEVEL%" == "0" goto init
+
+echo.
+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:findJavaFromJavaHome
+set JAVA_HOME=%JAVA_HOME:"=%
+set JAVA_EXE=%JAVA_HOME%/bin/java.exe
+
+if exist "%JAVA_EXE%" goto init
+
+echo.
+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME%
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:init
+@rem Get command-line arguments, handling Windows variants
+
+if not "%OS%" == "Windows_NT" goto win9xME_args
+
+:win9xME_args
+@rem Slurp the command line arguments.
+set CMD_LINE_ARGS=
+set _SKIP=2
+
+:win9xME_args_slurp
+if "x%~1" == "x" goto execute
+
+set CMD_LINE_ARGS=%*
+
+:execute
+@rem Setup the command line
+
+set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
+
+@rem Execute Gradle
+"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %CMD_LINE_ARGS%
+
+:end
+@rem End local scope for the variables with windows NT shell
+if "%ERRORLEVEL%"=="0" goto mainEnd
+
+:fail
+rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
+rem the _cmd.exe /c_ return code!
+if  not "" == "%GRADLE_EXIT_CONSOLE%" exit 1
+exit /b 1
+
+:mainEnd
+if "%OS%"=="Windows_NT" endlocal
+
+:omega
diff --git a/spring-boot/password-encoding/src/main/java/io/reflectoring/passwordencoding/PasswordEncodingSpringBootApplication.java b/spring-boot/password-encoding/src/main/java/io/reflectoring/passwordencoding/PasswordEncodingSpringBootApplication.java
new file mode 100644
index 0000000..950eb31
--- /dev/null
+++ b/spring-boot/password-encoding/src/main/java/io/reflectoring/passwordencoding/PasswordEncodingSpringBootApplication.java
@@ -0,0 +1,12 @@
+package io.reflectoring.passwordencoding;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class PasswordEncodingSpringBootApplication {
+
+  public static void main(String[] args) {
+    SpringApplication.run(PasswordEncodingSpringBootApplication.class, args);
+  }
+}
diff --git a/spring-boot/password-encoding/src/main/java/io/reflectoring/passwordencoding/authentication/DatabaseUserDetailPasswordService.java b/spring-boot/password-encoding/src/main/java/io/reflectoring/passwordencoding/authentication/DatabaseUserDetailPasswordService.java
new file mode 100644
index 0000000..8b6389f
--- /dev/null
+++ b/spring-boot/password-encoding/src/main/java/io/reflectoring/passwordencoding/authentication/DatabaseUserDetailPasswordService.java
@@ -0,0 +1,28 @@
+package io.reflectoring.passwordencoding.authentication;
+
+import org.springframework.security.core.userdetails.UserDetails;
+import org.springframework.security.core.userdetails.UserDetailsPasswordService;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+@Transactional
+@Service
+public class DatabaseUserDetailPasswordService implements UserDetailsPasswordService {
+
+  private final UserRepository userRepository;
+
+  private final UserDetailsMapper userDetailsMapper;
+
+  public DatabaseUserDetailPasswordService(
+      UserRepository userRepository, UserDetailsMapper userDetailsMapper) {
+    this.userRepository = userRepository;
+    this.userDetailsMapper = userDetailsMapper;
+  }
+
+  @Override
+  public UserDetails updatePassword(UserDetails user, String newPassword) {
+    UserCredentials userCredentials = userRepository.findByUsername(user.getUsername());
+    userCredentials.setPassword(newPassword);
+    return userDetailsMapper.toUserDetails(userCredentials);
+  }
+}
diff --git a/spring-boot/password-encoding/src/main/java/io/reflectoring/passwordencoding/authentication/DatabaseUserDetailsService.java b/spring-boot/password-encoding/src/main/java/io/reflectoring/passwordencoding/authentication/DatabaseUserDetailsService.java
new file mode 100644
index 0000000..91dbe8e
--- /dev/null
+++ b/spring-boot/password-encoding/src/main/java/io/reflectoring/passwordencoding/authentication/DatabaseUserDetailsService.java
@@ -0,0 +1,29 @@
+package io.reflectoring.passwordencoding.authentication;
+
+import org.springframework.security.core.userdetails.UserDetails;
+import org.springframework.security.core.userdetails.UserDetailsService;
+import org.springframework.security.core.userdetails.UsernameNotFoundException;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+@Service
+@Transactional
+public class DatabaseUserDetailsService implements UserDetailsService {
+
+  private final UserRepository userRepository;
+
+  private final UserDetailsMapper userDetailsMapper;
+
+  public DatabaseUserDetailsService(
+      UserRepository userRepository, UserDetailsMapper userDetailsMapper) {
+    this.userRepository = userRepository;
+    this.userDetailsMapper = userDetailsMapper;
+  }
+
+  @Override
+  public UserDetails loadUserByUsername(String username)
+          throws UsernameNotFoundException {
+    UserCredentials userCredentials = userRepository.findByUsername(username);
+    return userDetailsMapper.toUserDetails(userCredentials);
+  }
+}
diff --git a/spring-boot/password-encoding/src/main/java/io/reflectoring/passwordencoding/authentication/UserCredentials.java b/spring-boot/password-encoding/src/main/java/io/reflectoring/passwordencoding/authentication/UserCredentials.java
new file mode 100644
index 0000000..54a2ee0
--- /dev/null
+++ b/spring-boot/password-encoding/src/main/java/io/reflectoring/passwordencoding/authentication/UserCredentials.java
@@ -0,0 +1,31 @@
+package io.reflectoring.passwordencoding.authentication;
+
+import lombok.AllArgsConstructor;
+import lombok.Builder;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+import javax.persistence.*;
+import java.util.Set;
+
+@Entity
+@Data
+@NoArgsConstructor
+@AllArgsConstructor
+@Builder
+@Table(name = "users")
+public class UserCredentials {
+
+  @Id private String username;
+
+  private String password;
+
+  boolean enabled;
+
+  @ElementCollection
+  @JoinTable(
+      name = "authorities",
+      joinColumns = {@JoinColumn(name = "username")})
+  @Column(name = "authority")
+  private Set<String> roles;
+}
diff --git a/spring-boot/password-encoding/src/main/java/io/reflectoring/passwordencoding/authentication/UserDetailsMapper.java b/spring-boot/password-encoding/src/main/java/io/reflectoring/passwordencoding/authentication/UserDetailsMapper.java
new file mode 100644
index 0000000..f3828ab
--- /dev/null
+++ b/spring-boot/password-encoding/src/main/java/io/reflectoring/passwordencoding/authentication/UserDetailsMapper.java
@@ -0,0 +1,17 @@
+package io.reflectoring.passwordencoding.authentication;
+
+import org.springframework.security.core.userdetails.User;
+import org.springframework.security.core.userdetails.UserDetails;
+import org.springframework.stereotype.Component;
+
+@Component
+class UserDetailsMapper {
+
+  UserDetails toUserDetails(UserCredentials userCredentials) {
+
+    return User.withUsername(userCredentials.getUsername())
+        .password(userCredentials.getPassword())
+        .roles(userCredentials.getRoles().toArray(String[]::new))
+        .build();
+  }
+}
diff --git a/spring-boot/password-encoding/src/main/java/io/reflectoring/passwordencoding/authentication/UserRepository.java b/spring-boot/password-encoding/src/main/java/io/reflectoring/passwordencoding/authentication/UserRepository.java
new file mode 100644
index 0000000..b916c2c
--- /dev/null
+++ b/spring-boot/password-encoding/src/main/java/io/reflectoring/passwordencoding/authentication/UserRepository.java
@@ -0,0 +1,10 @@
+package io.reflectoring.passwordencoding.authentication;
+
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.transaction.annotation.Transactional;
+
+@Transactional
+public interface UserRepository extends JpaRepository<UserCredentials, String> {
+
+  UserCredentials findByUsername(String username);
+}
diff --git a/spring-boot/password-encoding/src/main/java/io/reflectoring/passwordencoding/configuration/SecurityConfiguration.java b/spring-boot/password-encoding/src/main/java/io/reflectoring/passwordencoding/configuration/SecurityConfiguration.java
new file mode 100644
index 0000000..da5291c
--- /dev/null
+++ b/spring-boot/password-encoding/src/main/java/io/reflectoring/passwordencoding/configuration/SecurityConfiguration.java
@@ -0,0 +1,82 @@
+package io.reflectoring.passwordencoding.configuration;
+
+import io.reflectoring.passwordencoding.authentication.DatabaseUserDetailPasswordService;
+import io.reflectoring.passwordencoding.authentication.DatabaseUserDetailsService;
+import io.reflectoring.passwordencoding.workfactor.BcCryptWorkFactorService;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.security.authentication.AuthenticationProvider;
+import org.springframework.security.authentication.dao.DaoAuthenticationProvider;
+import org.springframework.security.config.annotation.web.builders.HttpSecurity;
+import org.springframework.security.config.annotation.web.configuration.EnableWebSecurity;
+import org.springframework.security.config.annotation.web.configuration.WebSecurityConfigurerAdapter;
+import org.springframework.security.crypto.argon2.Argon2PasswordEncoder;
+import org.springframework.security.crypto.bcrypt.BCryptPasswordEncoder;
+import org.springframework.security.crypto.password.*;
+import org.springframework.security.crypto.scrypt.SCryptPasswordEncoder;
+
+import java.util.HashMap;
+import java.util.Map;
+
+@Configuration
+@EnableWebSecurity
+class SecurityConfiguration extends WebSecurityConfigurerAdapter {
+
+  private final BcCryptWorkFactorService bcCryptWorkFactorService;
+  private final DatabaseUserDetailsService databaseUserDetailsService;
+  private final DatabaseUserDetailPasswordService databaseUserDetailPasswordService;
+
+  public SecurityConfiguration(
+          BcCryptWorkFactorService bcCryptWorkFactorService,
+          DatabaseUserDetailsService databaseUserDetailsService,
+          DatabaseUserDetailPasswordService databaseUserDetailPasswordService) {
+    this.bcCryptWorkFactorService = bcCryptWorkFactorService;
+    this.databaseUserDetailsService = databaseUserDetailsService;
+    this.databaseUserDetailPasswordService = databaseUserDetailPasswordService;
+  }
+
+  @Override
+  protected void configure(HttpSecurity httpSecurity) throws Exception {
+    httpSecurity
+        .csrf()
+        .disable()
+        .authorizeRequests()
+        .antMatchers("/registration")
+        .permitAll()
+        .anyRequest()
+        .authenticated()
+        .and()
+        .httpBasic();
+
+    httpSecurity.headers().frameOptions().disable();
+  }
+
+  @Bean
+  public PasswordEncoder passwordEncoder() {
+    // we must use deprecated encoder to support their encoding
+    String encodingId = "bcrypt";
+    Map<String, PasswordEncoder> encoders = new HashMap<>();
+    encoders.put(encodingId, new BCryptPasswordEncoder(bcCryptWorkFactorService.calculateStrength()));
+    encoders.put("ldap", new LdapShaPasswordEncoder());
+    encoders.put("MD4", new Md4PasswordEncoder());
+    encoders.put("MD5", new MessageDigestPasswordEncoder("MD5"));
+    encoders.put("noop", NoOpPasswordEncoder.getInstance());
+    encoders.put("pbkdf2", new Pbkdf2PasswordEncoder());
+    encoders.put("scrypt", new SCryptPasswordEncoder());
+    encoders.put("SHA-1", new MessageDigestPasswordEncoder("SHA-1"));
+    encoders.put("SHA-256", new MessageDigestPasswordEncoder("SHA-256"));
+    encoders.put("sha256", new StandardPasswordEncoder());
+    encoders.put("argon2", new Argon2PasswordEncoder());
+
+    return new DelegatingPasswordEncoder(encodingId, encoders);
+  }
+
+  @Bean
+  public AuthenticationProvider daoAuthenticationProvider() {
+    DaoAuthenticationProvider provider = new DaoAuthenticationProvider();
+    provider.setPasswordEncoder(passwordEncoder());
+    provider.setUserDetailsPasswordService(this.databaseUserDetailPasswordService);
+    provider.setUserDetailsService(this.databaseUserDetailsService);
+    return provider;
+  }
+}
diff --git a/spring-boot/password-encoding/src/main/java/io/reflectoring/passwordencoding/encoder/Argon2Example.java b/spring-boot/password-encoding/src/main/java/io/reflectoring/passwordencoding/encoder/Argon2Example.java
new file mode 100644
index 0000000..7441b42
--- /dev/null
+++ b/spring-boot/password-encoding/src/main/java/io/reflectoring/passwordencoding/encoder/Argon2Example.java
@@ -0,0 +1,18 @@
+package io.reflectoring.passwordencoding.encoder;
+
+import org.springframework.security.crypto.argon2.Argon2PasswordEncoder;
+
+class Argon2Example {
+
+  public String encode(String plainPassword) {
+    int saltLength = 16; // salt length in bytes
+    int hashLength = 32; // hash length in bytes
+    int parallelism = 1; // currently is not supported
+    int memory = 4096; // memory costs
+    int iterations = 3;
+
+    Argon2PasswordEncoder argon2PasswordEncoder =
+        new Argon2PasswordEncoder(saltLength, hashLength, parallelism, memory, iterations);
+    return argon2PasswordEncoder.encode(plainPassword);
+  }
+}
diff --git a/spring-boot/password-encoding/src/main/java/io/reflectoring/passwordencoding/encoder/BCryptExample.java b/spring-boot/password-encoding/src/main/java/io/reflectoring/passwordencoding/encoder/BCryptExample.java
new file mode 100644
index 0000000..c16da50
--- /dev/null
+++ b/spring-boot/password-encoding/src/main/java/io/reflectoring/passwordencoding/encoder/BCryptExample.java
@@ -0,0 +1,15 @@
+package io.reflectoring.passwordencoding.encoder;
+
+import org.springframework.security.crypto.bcrypt.BCryptPasswordEncoder;
+
+import java.security.SecureRandom;
+
+class BCryptExample {
+
+  public String encode(String plainPassword) {
+    int strength = 10;
+    BCryptPasswordEncoder bCryptPasswordEncoder =
+        new BCryptPasswordEncoder(strength, new SecureRandom());
+    return bCryptPasswordEncoder.encode(plainPassword);
+  }
+}
diff --git a/spring-boot/password-encoding/src/main/java/io/reflectoring/passwordencoding/encoder/Pbkdf2Example.java b/spring-boot/password-encoding/src/main/java/io/reflectoring/passwordencoding/encoder/Pbkdf2Example.java
new file mode 100644
index 0000000..ced80d3
--- /dev/null
+++ b/spring-boot/password-encoding/src/main/java/io/reflectoring/passwordencoding/encoder/Pbkdf2Example.java
@@ -0,0 +1,17 @@
+package io.reflectoring.passwordencoding.encoder;
+
+import org.springframework.security.crypto.password.Pbkdf2PasswordEncoder;
+
+class Pbkdf2Example {
+
+  public String encode(String plainPassword) {
+
+    String pepper = "pepper"; // secret key used by password encoding
+    int iterations = 200000; // number of hash iteration
+    int hashWidth = 256; // hash with in bits
+
+    Pbkdf2PasswordEncoder pbkdf2PasswordEncoder =
+        new Pbkdf2PasswordEncoder(pepper, iterations, hashWidth);
+    return pbkdf2PasswordEncoder.encode(plainPassword);
+  }
+}
diff --git a/spring-boot/password-encoding/src/main/java/io/reflectoring/passwordencoding/encoder/SCryptExample.java b/spring-boot/password-encoding/src/main/java/io/reflectoring/passwordencoding/encoder/SCryptExample.java
new file mode 100644
index 0000000..83f5203
--- /dev/null
+++ b/spring-boot/password-encoding/src/main/java/io/reflectoring/passwordencoding/encoder/SCryptExample.java
@@ -0,0 +1,18 @@
+package io.reflectoring.passwordencoding.encoder;
+
+import org.springframework.security.crypto.scrypt.SCryptPasswordEncoder;
+
+class SCryptExample {
+
+  public String encode(String plainPassword) {
+    int cpuCost = (int) Math.pow(2, 14); // factor to increase CPU costs
+    int memoryCost = 8; // factor to increases memory usage
+    int parallelization = 1; // currently  nor supported by Spring Security
+    int keyLength = 32; // key length in bytes
+    int saltLength = 64; // salt length in bytes
+
+    SCryptPasswordEncoder sCryptPasswordEncoder =
+        new SCryptPasswordEncoder(cpuCost, memoryCost, parallelization, keyLength, saltLength);
+    return sCryptPasswordEncoder.encode(plainPassword);
+  }
+}
diff --git a/spring-boot/password-encoding/src/main/java/io/reflectoring/passwordencoding/resources/Car.java b/spring-boot/password-encoding/src/main/java/io/reflectoring/passwordencoding/resources/Car.java
new file mode 100644
index 0000000..11c3186
--- /dev/null
+++ b/spring-boot/password-encoding/src/main/java/io/reflectoring/passwordencoding/resources/Car.java
@@ -0,0 +1,16 @@
+package io.reflectoring.passwordencoding.resources;
+
+import lombok.AllArgsConstructor;
+import lombok.Builder;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+@NoArgsConstructor
+@Data
+@Builder
+@AllArgsConstructor
+class Car {
+
+  private String name;
+  private String color;
+}
diff --git a/spring-boot/password-encoding/src/main/java/io/reflectoring/passwordencoding/resources/CarResources.java b/spring-boot/password-encoding/src/main/java/io/reflectoring/passwordencoding/resources/CarResources.java
new file mode 100644
index 0000000..f8a64a4
--- /dev/null
+++ b/spring-boot/password-encoding/src/main/java/io/reflectoring/passwordencoding/resources/CarResources.java
@@ -0,0 +1,15 @@
+package io.reflectoring.passwordencoding.resources;
+
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+import java.util.Set;
+
+@RestController
+class CarResources {
+
+  @GetMapping("/cars")
+  public Set<Car> cars() {
+    return Set.of(new Car("vw", "black"), new Car("bmw", "white"));
+  }
+}
diff --git a/spring-boot/password-encoding/src/main/java/io/reflectoring/passwordencoding/resources/RegistrationResource.java b/spring-boot/password-encoding/src/main/java/io/reflectoring/passwordencoding/resources/RegistrationResource.java
new file mode 100644
index 0000000..131c638
--- /dev/null
+++ b/spring-boot/password-encoding/src/main/java/io/reflectoring/passwordencoding/resources/RegistrationResource.java
@@ -0,0 +1,37 @@
+package io.reflectoring.passwordencoding.resources;
+
+import io.reflectoring.passwordencoding.authentication.UserCredentials;
+import io.reflectoring.passwordencoding.authentication.UserRepository;
+import org.springframework.http.HttpStatus;
+import org.springframework.security.crypto.password.PasswordEncoder;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.RequestBody;
+import org.springframework.web.bind.annotation.ResponseStatus;
+import org.springframework.web.bind.annotation.RestController;
+
+import java.util.Set;
+
+@RestController
+class RegistrationResource {
+
+  private final UserRepository userRepository;
+  private final PasswordEncoder passwordEncoder;
+
+  public RegistrationResource(UserRepository userRepository, PasswordEncoder passwordEncoder) {
+    this.userRepository = userRepository;
+    this.passwordEncoder = passwordEncoder;
+  }
+
+  @PostMapping("/registration")
+  @ResponseStatus(code = HttpStatus.CREATED)
+  public void register(@RequestBody UserCredentialsDto userCredentialsDto) {
+    UserCredentials user =
+        UserCredentials.builder()
+            .enabled(true)
+            .username(userCredentialsDto.getUsername())
+            .password(passwordEncoder.encode(userCredentialsDto.getPassword()))
+            .roles(Set.of("USER"))
+            .build();
+    userRepository.save(user);
+  }
+}
diff --git a/spring-boot/password-encoding/src/main/java/io/reflectoring/passwordencoding/resources/UserCredentialsDto.java b/spring-boot/password-encoding/src/main/java/io/reflectoring/passwordencoding/resources/UserCredentialsDto.java
new file mode 100644
index 0000000..ce59f42
--- /dev/null
+++ b/spring-boot/password-encoding/src/main/java/io/reflectoring/passwordencoding/resources/UserCredentialsDto.java
@@ -0,0 +1,15 @@
+package io.reflectoring.passwordencoding.resources;
+
+import lombok.AllArgsConstructor;
+import lombok.Builder;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+@Data
+@Builder
+@AllArgsConstructor
+@NoArgsConstructor
+class UserCredentialsDto {
+  private String username;
+  private String password;
+}
diff --git a/spring-boot/password-encoding/src/main/java/io/reflectoring/passwordencoding/workfactor/BcCryptWorkFactorService.java b/spring-boot/password-encoding/src/main/java/io/reflectoring/passwordencoding/workfactor/BcCryptWorkFactorService.java
new file mode 100644
index 0000000..403e0c7
--- /dev/null
+++ b/spring-boot/password-encoding/src/main/java/io/reflectoring/passwordencoding/workfactor/BcCryptWorkFactorService.java
@@ -0,0 +1,101 @@
+package io.reflectoring.passwordencoding.workfactor;
+
+import com.google.common.base.Stopwatch;
+import org.springframework.security.crypto.bcrypt.BCryptPasswordEncoder;
+import org.springframework.stereotype.Component;
+
+import java.util.concurrent.TimeUnit;
+
+@Component
+public class BcCryptWorkFactorService {
+
+  private static final String TEST_PASSWORD = "my password";
+  private static final int GOAL_MILLISECONDS_PER_PASSWORD = 1000;
+  private static final int MIN_STRENGTH = 4;
+  private static final int MAX_STRENGTH = 31;
+
+  /**
+   * Calculates the strength (a.k.a. log rounds) for the BCrypt Algorithm, so that password encoding
+   * takes about 1s. This method uses the divide-and-conquer algorithm.
+   */
+  public BcryptWorkFactor calculateStrengthDivideAndConquer() {
+    return calculateStrengthDivideAndConquer(
+        new BcryptWorkFactor(MIN_STRENGTH, Integer.MIN_VALUE),
+        new BcryptWorkFactor(MAX_STRENGTH, Integer.MAX_VALUE));
+  }
+
+  private BcryptWorkFactor calculateStrengthDivideAndConquer(
+      BcryptWorkFactor smallFactor, BcryptWorkFactor bigFactor) {
+    if (bigFactor.getStrength() - smallFactor.getStrength() == 1) {
+      return getClosestStrength(smallFactor, bigFactor);
+    }
+    int midStrength =
+        (bigFactor.getStrength() - smallFactor.getStrength()) / 2 + smallFactor.getStrength();
+    long duration = calculateDuration(midStrength);
+    BcryptWorkFactor midFactor = new BcryptWorkFactor(midStrength, duration);
+    if (duration < GOAL_MILLISECONDS_PER_PASSWORD) {
+      return calculateStrengthDivideAndConquer(midFactor, bigFactor);
+    }
+    return calculateStrengthDivideAndConquer(smallFactor, midFactor);
+  }
+
+  private BcryptWorkFactor getClosestStrength(
+      BcryptWorkFactor smallFactor, BcryptWorkFactor bigFactor) {
+    if (isPreviousDurationCloserToGoal(smallFactor.getDuration(), bigFactor.getDuration())) {
+      return smallFactor;
+    }
+    return bigFactor;
+  }
+
+  private long calculateDuration(int strength) {
+    BCryptPasswordEncoder bCryptPasswordEncoder = new BCryptPasswordEncoder(strength);
+    Stopwatch stopwatch = Stopwatch.createStarted();
+    bCryptPasswordEncoder.encode(TEST_PASSWORD);
+    stopwatch.stop();
+    return stopwatch.elapsed(TimeUnit.MILLISECONDS);
+  }
+
+  /**
+   * Calculates the strength (a.k.a. log rounds) for the BCrypt Algorithm, so that password encoding
+   * takes about 1s. This method iterates over strength from 4 to 31 and calculates the duration of
+   * password encoding for every value of strength. It returns the first strength, that takes more
+   * than 1s
+   */
+  public int calculateStrength() {
+    for (int strength = MIN_STRENGTH; strength <= MAX_STRENGTH; strength++) {
+
+      long duration = calculateDuration(strength);
+      if (duration >= GOAL_MILLISECONDS_PER_PASSWORD) {
+        return strength;
+      }
+    }
+    throw new RuntimeException(
+        String.format(
+            "Could not find suitable round number for bcrypt encoding. The encoding with %d rounds"
+                + " takes less than %d ms.",
+            MAX_STRENGTH, GOAL_MILLISECONDS_PER_PASSWORD));
+  }
+
+  /**
+   * @param previousDuration duration from previous iteration
+   * @param currentDuration duration of current iteration
+   * @param strength current strength
+   * @return return the current strength, if current duration is closer to
+   *     GOAL_MILLISECONDS_PER_PASSWORD, otherwise current strength-1.
+   */
+  int getStrength(long previousDuration, long currentDuration, int strength) {
+    if (isPreviousDurationCloserToGoal(previousDuration, currentDuration)) {
+      return strength - 1;
+    } else {
+      return strength;
+    }
+  }
+
+  /**
+   * return true, if previousDuration is closer to the goal than currentDuration, false otherwise.
+   */
+  boolean isPreviousDurationCloserToGoal(long previousDuration, long currentDuration) {
+    return Math.abs(GOAL_MILLISECONDS_PER_PASSWORD - previousDuration)
+        < Math.abs(GOAL_MILLISECONDS_PER_PASSWORD - currentDuration);
+  }
+}
diff --git a/spring-boot/password-encoding/src/main/java/io/reflectoring/passwordencoding/workfactor/BcryptWorkFactor.java b/spring-boot/password-encoding/src/main/java/io/reflectoring/passwordencoding/workfactor/BcryptWorkFactor.java
new file mode 100644
index 0000000..f966548
--- /dev/null
+++ b/spring-boot/password-encoding/src/main/java/io/reflectoring/passwordencoding/workfactor/BcryptWorkFactor.java
@@ -0,0 +1,12 @@
+package io.reflectoring.passwordencoding.workfactor;
+
+import lombok.AllArgsConstructor;
+import lombok.Data;
+
+@Data
+@AllArgsConstructor
+class BcryptWorkFactor {
+
+  private int strength;
+  private long duration;
+}
diff --git a/spring-boot/password-encoding/src/main/java/io/reflectoring/passwordencoding/workfactor/Pbkdf2WorkFactorService.java b/spring-boot/password-encoding/src/main/java/io/reflectoring/passwordencoding/workfactor/Pbkdf2WorkFactorService.java
new file mode 100644
index 0000000..c094b00
--- /dev/null
+++ b/spring-boot/password-encoding/src/main/java/io/reflectoring/passwordencoding/workfactor/Pbkdf2WorkFactorService.java
@@ -0,0 +1,41 @@
+package io.reflectoring.passwordencoding.workfactor;
+
+import com.google.common.base.Stopwatch;
+import org.springframework.security.crypto.password.Pbkdf2PasswordEncoder;
+import org.springframework.stereotype.Component;
+
+import java.util.concurrent.TimeUnit;
+
+@Component
+class Pbkdf2WorkFactorService {
+
+  private static final String TEST_PASSWORD = "my password";
+  private static final String NO_ADDITIONAL_SECRET = "";
+  private static final int GOAL_MILLISECONDS_PER_PASSWORD = 1000;
+  private static final int HASH_WIDTH = 256;
+  private static final int ITERATION_STEP = 5000;
+
+  /**
+   * Finds the number of Iteration for the {@link Pbkdf2PasswordEncoder} to get the duration of
+   * password encoding close to 1s. The Calculation does not use any secret (pepper) and applies
+   * hash algorithm SHA256.
+   */
+  public int calculateIteration() {
+
+    int iterationNumber = 150000;
+    while (true) {
+      Pbkdf2PasswordEncoder pbkdf2PasswordEncoder =
+          new Pbkdf2PasswordEncoder(NO_ADDITIONAL_SECRET, iterationNumber, HASH_WIDTH);
+
+      Stopwatch stopwatch = Stopwatch.createStarted();
+      pbkdf2PasswordEncoder.encode(TEST_PASSWORD);
+      stopwatch.stop();
+
+      long duration = stopwatch.elapsed(TimeUnit.MILLISECONDS);
+      if (duration > GOAL_MILLISECONDS_PER_PASSWORD) {
+        return iterationNumber;
+      }
+      iterationNumber += ITERATION_STEP;
+    }
+  }
+}
diff --git a/spring-boot/password-encoding/src/main/resources/application.yaml b/spring-boot/password-encoding/src/main/resources/application.yaml
new file mode 100644
index 0000000..3d20cdb
--- /dev/null
+++ b/spring-boot/password-encoding/src/main/resources/application.yaml
@@ -0,0 +1,11 @@
+spring:
+  h2:
+    console:
+      enabled: true
+  datasource:
+    url: jdbc:h2:mem:testdb
+    driverClassName: org.h2.Driver
+    username: sa
+    password:
+  jpa:
+    database-platform: org.hibernate.dialect.H2Dialect
diff --git a/spring-boot/password-encoding/src/main/resources/db/migration/V1_1__create_user_tables.sql b/spring-boot/password-encoding/src/main/resources/db/migration/V1_1__create_user_tables.sql
new file mode 100644
index 0000000..e7ace3a
--- /dev/null
+++ b/spring-boot/password-encoding/src/main/resources/db/migration/V1_1__create_user_tables.sql
@@ -0,0 +1,14 @@
+create table users
+(
+    username varchar_ignorecase(50) not null primary key,
+    password varchar(2048)          not null,
+    enabled  boolean                not null
+);
+
+create table authorities
+(
+    username  varchar_ignorecase(50) not null,
+    authority varchar_ignorecase(50) not null,
+    constraint fk_authorities_users foreign key (username) references users (username)
+);
+create unique index ix_auth_username on authorities (username, authority);
\ No newline at end of file
diff --git a/spring-boot/password-encoding/src/main/resources/db/migration/V1_2__add user.sql b/spring-boot/password-encoding/src/main/resources/db/migration/V1_2__add user.sql
new file mode 100644
index 0000000..254e7c0
--- /dev/null
+++ b/spring-boot/password-encoding/src/main/resources/db/migration/V1_2__add user.sql	
@@ -0,0 +1,15 @@
+insert into users (username, password, enabled)
+VALUES ('admin', '{bcrypt}$2a$10$4V9kA793Pi2xf94dYFgKWuw8ukyETxWb7tZ4/mfco9sWkwvBQndxW', true);
+insert into users (username, password, enabled)
+VALUES ('user',
+        '{SHA-256}{4Cc0+yDMHnTUy+zOHeMH7yaPhxvlJT//tQTwEhyegiQ=}446d06130bfc254527a7bbd95b50595a977c0058110f8dccb54bd273d99325b8',
+        true);
+insert into users (username, password, enabled)
+VALUES ('user with working factor 5', '{bcrypt}$2a$05$Zz4rToG8YXKMbuAPgm3qj.HpTFsGEdZHhCf9ikIHAoI5elX7ajNm.', true);
+insert into users (username, password, enabled)
+VALUES ('user with sha1 encoding',
+        '{SHA-1}{6tND0AZfFH3aE1VDg7QkWT6DzFg/NUHtukntgwu8JV4=}804c6e8efebf4e91f88e3baf9fd383e28a21378c', true);
+insert into users (username, password, enabled)
+VALUES ('scrypt user',
+        '{scrypt}$e0801$fUx3MxN07zdH3UyARJqOwv3WiWCvE7f6qRm9A5KQfNo5ovSwxMHknQ4vERO4csj/I3imG2HJQg1HHp7Rqzbp7g==$Fm5F9PSoE/jBYLOmnCJcvX1Euf952r5b3BjAl+SwQMs=',
+        true);
\ No newline at end of file
diff --git a/spring-boot/password-encoding/src/test/java/io/reflectoring/passwordencoding/authentication/UserDetailsMapperTest.java b/spring-boot/password-encoding/src/test/java/io/reflectoring/passwordencoding/authentication/UserDetailsMapperTest.java
new file mode 100644
index 0000000..dce400e
--- /dev/null
+++ b/spring-boot/password-encoding/src/test/java/io/reflectoring/passwordencoding/authentication/UserDetailsMapperTest.java
@@ -0,0 +1,33 @@
+package io.reflectoring.passwordencoding.authentication;
+
+import org.junit.jupiter.api.Test;
+import org.springframework.security.core.userdetails.UserDetails;
+
+import java.util.Set;
+
+import static org.assertj.core.api.AssertionsForInterfaceTypes.assertThat;
+
+class UserDetailsMapperTest {
+
+  private UserDetailsMapper userDetailsMapper = new UserDetailsMapper();
+
+  @Test
+  void toUserDetails() {
+    // given
+    UserCredentials userCredentials =
+        UserCredentials.builder()
+            .enabled(true)
+            .password("password")
+            .username("user")
+            .roles(Set.of("USER", "ADMIN"))
+            .build();
+
+    // when
+    UserDetails userDetails = userDetailsMapper.toUserDetails(userCredentials);
+
+    // then
+    assertThat(userDetails.getUsername()).isEqualTo("user");
+    assertThat(userDetails.getPassword()).isEqualTo("password");
+    assertThat(userDetails.isEnabled()).isTrue();
+  }
+}
diff --git a/spring-boot/password-encoding/src/test/java/io/reflectoring/passwordencoding/authentication/UserRepositoryTest.java b/spring-boot/password-encoding/src/test/java/io/reflectoring/passwordencoding/authentication/UserRepositoryTest.java
new file mode 100644
index 0000000..38970de
--- /dev/null
+++ b/spring-boot/password-encoding/src/test/java/io/reflectoring/passwordencoding/authentication/UserRepositoryTest.java
@@ -0,0 +1,25 @@
+package io.reflectoring.passwordencoding.authentication;
+
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.autoconfigure.orm.jpa.DataJpaTest;
+
+import static org.assertj.core.api.AssertionsForInterfaceTypes.assertThat;
+
+@DataJpaTest
+class UserRepositoryTest {
+
+  @Autowired private UserRepository userRepository;
+
+  @Test
+  void findUserByUsername() {
+    // given
+    String username = "user";
+
+    // when
+    UserCredentials userCredentials = userRepository.findByUsername(username);
+
+    // then
+    assertThat(userCredentials).isNotNull();
+  }
+}
diff --git a/spring-boot/password-encoding/src/test/java/io/reflectoring/passwordencoding/encoder/Argon2ExampleTest.java b/spring-boot/password-encoding/src/test/java/io/reflectoring/passwordencoding/encoder/Argon2ExampleTest.java
new file mode 100644
index 0000000..cc12d93
--- /dev/null
+++ b/spring-boot/password-encoding/src/test/java/io/reflectoring/passwordencoding/encoder/Argon2ExampleTest.java
@@ -0,0 +1,22 @@
+package io.reflectoring.passwordencoding.encoder;
+
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.AssertionsForClassTypes.assertThat;
+
+class Argon2ExampleTest {
+
+  private Argon2Example argon2Example = new Argon2Example();
+
+  @Test
+  void encode() {
+    // given
+    String plainPassword = "password";
+
+    // when
+    String actual = argon2Example.encode(plainPassword);
+
+    // then
+    assertThat(actual).startsWith("$argon2id$v=19$m=4096,t=3,p=1");
+  }
+}
diff --git a/spring-boot/password-encoding/src/test/java/io/reflectoring/passwordencoding/encoder/BCryptExampleTest.java b/spring-boot/password-encoding/src/test/java/io/reflectoring/passwordencoding/encoder/BCryptExampleTest.java
new file mode 100644
index 0000000..7fa6bc0
--- /dev/null
+++ b/spring-boot/password-encoding/src/test/java/io/reflectoring/passwordencoding/encoder/BCryptExampleTest.java
@@ -0,0 +1,22 @@
+package io.reflectoring.passwordencoding.encoder;
+
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.AssertionsForClassTypes.assertThat;
+
+class BCryptExampleTest {
+
+  private BCryptExample bcryptExample = new BCryptExample();
+
+  @Test
+  void encode() {
+    // given
+    String plainPassword = "password";
+
+    // when
+    String encoded = bcryptExample.encode(plainPassword);
+
+    // then
+    assertThat(encoded).startsWith("$2a$10");
+  }
+}
diff --git a/spring-boot/password-encoding/src/test/java/io/reflectoring/passwordencoding/encoder/Pbkdf2ExampleTest.java b/spring-boot/password-encoding/src/test/java/io/reflectoring/passwordencoding/encoder/Pbkdf2ExampleTest.java
new file mode 100644
index 0000000..3ccd734
--- /dev/null
+++ b/spring-boot/password-encoding/src/test/java/io/reflectoring/passwordencoding/encoder/Pbkdf2ExampleTest.java
@@ -0,0 +1,22 @@
+package io.reflectoring.passwordencoding.encoder;
+
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.AssertionsForClassTypes.assertThat;
+
+class Pbkdf2ExampleTest {
+
+  private Pbkdf2Example pbkdf2Example = new Pbkdf2Example();
+
+  @Test
+  void encode() {
+    // given
+    String plainPassword = "plainPassword";
+
+    // when
+    String actual = pbkdf2Example.encode(plainPassword);
+
+    // then
+    assertThat(actual).hasSize(80);
+  }
+}
diff --git a/spring-boot/password-encoding/src/test/java/io/reflectoring/passwordencoding/encoder/SCryptExampleTest.java b/spring-boot/password-encoding/src/test/java/io/reflectoring/passwordencoding/encoder/SCryptExampleTest.java
new file mode 100644
index 0000000..0ddb647
--- /dev/null
+++ b/spring-boot/password-encoding/src/test/java/io/reflectoring/passwordencoding/encoder/SCryptExampleTest.java
@@ -0,0 +1,23 @@
+package io.reflectoring.passwordencoding.encoder;
+
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.AssertionsForClassTypes.assertThat;
+
+class SCryptExampleTest {
+
+  private SCryptExample sCryptExample = new SCryptExample();
+
+  @Test
+  void encode() {
+    // given
+    String plainPassword = "password";
+
+    // when
+    String actual = sCryptExample.encode(plainPassword);
+
+    // then
+    assertThat(actual).hasSize(140);
+    assertThat(actual).startsWith("$e0801");
+  }
+}
diff --git a/spring-boot/password-encoding/src/test/java/io/reflectoring/passwordencoding/resources/CarResourcesTest.java b/spring-boot/password-encoding/src/test/java/io/reflectoring/passwordencoding/resources/CarResourcesTest.java
new file mode 100644
index 0000000..36b4c55
--- /dev/null
+++ b/spring-boot/password-encoding/src/test/java/io/reflectoring/passwordencoding/resources/CarResourcesTest.java
@@ -0,0 +1,91 @@
+package io.reflectoring.passwordencoding.resources;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import io.reflectoring.passwordencoding.authentication.UserCredentials;
+import io.reflectoring.passwordencoding.authentication.UserRepository;
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.autoconfigure.web.servlet.AutoConfigureMockMvc;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.http.MediaType;
+import org.springframework.test.web.servlet.MockMvc;
+import org.springframework.transaction.annotation.Transactional;
+
+import static org.assertj.core.api.AssertionsForInterfaceTypes.assertThat;
+import static org.springframework.security.test.web.servlet.request.SecurityMockMvcRequestPostProcessors.httpBasic;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.post;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
+
+@SpringBootTest
+@AutoConfigureMockMvc
+@Transactional
+class CarResourcesTest {
+
+  @Autowired private MockMvc mockMvc;
+
+  @Autowired private ObjectMapper objectMapper;
+
+  @Autowired private UserRepository userRepository;
+
+  @Test
+  void getCarsShouldReturnUnauthorizedIfTheRequestHasNoBasicAuthentication() throws Exception {
+    mockMvc.perform(get("/cars")).andExpect(status().isUnauthorized());
+  }
+
+  @Test
+  void getCarsShouldReturnCarsForTheAuthenticatedUser() throws Exception {
+    mockMvc.perform(get("/cars").with(httpBasic("user", "password"))).andExpect(status().isOk());
+  }
+
+  @Test
+  void registrationShouldReturnCreated() throws Exception {
+
+    // register
+    UserCredentialsDto userCredentialsDto =
+        UserCredentialsDto.builder().username("toyota").password("my secret").build();
+    mockMvc
+        .perform(
+            post("/registration")
+                .contentType(MediaType.APPLICATION_JSON_VALUE)
+                .content(objectMapper.writeValueAsString(userCredentialsDto)))
+        .andExpect(status().isCreated());
+  }
+
+  @Test
+  void registrationShouldReturnUnauthorizedWithWrongCredentials() throws Exception {
+
+    mockMvc
+        .perform(get("/cars").with(httpBasic("user", "wrong password")))
+        .andExpect(status().isUnauthorized());
+  }
+
+  @Test
+  void getCarsShouldUpdatePasswordFromWorkingFactor5toHigherValue() throws Exception {
+    mockMvc
+        .perform(get("/cars").with(httpBasic("user with working factor 5", "password")))
+        .andExpect(status().isOk());
+
+    UserCredentials userCredentials = userRepository.findByUsername("user with working factor 5");
+    // we don't know what strength the BcCryptWorkFactorService returns,
+    // but it should be more than 5
+    assertThat(userCredentials.getPassword()).doesNotStartWith("{bcrypt}$2a$05");
+  }
+
+  @Test
+  void getCarsShouldMigrateSha1PasswordToBcrypt() throws Exception {
+    mockMvc
+        .perform(get("/cars").with(httpBasic("user with sha1 encoding", "password")))
+        .andExpect(status().isOk());
+
+    UserCredentials userCredentials = userRepository.findByUsername("user with sha1 encoding");
+    assertThat(userCredentials.getPassword()).startsWith("{bcrypt}");
+  }
+
+  @Test
+  void getCarsShouldReturnOkForScryptUser() throws Exception {
+    mockMvc
+        .perform(get("/cars").with(httpBasic("scrypt user", "password")))
+        .andExpect(status().isOk());
+  }
+}
diff --git a/spring-boot/password-encoding/src/test/java/io/reflectoring/passwordencoding/workfactor/BcCryptWorkFactorServiceTest.java b/spring-boot/password-encoding/src/test/java/io/reflectoring/passwordencoding/workfactor/BcCryptWorkFactorServiceTest.java
new file mode 100644
index 0000000..54e64bd
--- /dev/null
+++ b/spring-boot/password-encoding/src/test/java/io/reflectoring/passwordencoding/workfactor/BcCryptWorkFactorServiceTest.java
@@ -0,0 +1,119 @@
+package io.reflectoring.passwordencoding.workfactor;
+
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.AssertionsForClassTypes.assertThat;
+
+class BcCryptWorkFactorServiceTest {
+
+  private BcCryptWorkFactorService bcCryptWorkFactorService = new BcCryptWorkFactorService();
+
+  @Test
+  void calculateStrength() {
+    // given
+
+    // when
+    int strength = bcCryptWorkFactorService.calculateStrength();
+
+    // then
+    assertThat(strength).isBetween(4, 31);
+  }
+
+  @Test
+  void calculateStrengthBi() {
+    // given
+
+    // when
+    BcryptWorkFactor bcryptWorkFactor =
+        bcCryptWorkFactorService.calculateStrengthDivideAndConquer();
+
+    // then
+    assertThat(bcryptWorkFactor.getStrength()).isBetween(4, 31);
+  }
+
+  @Test
+  void findCloserToShouldReturnNumber1IfItCloserToGoalThanNumber2() {
+    // given
+    int number1 = 950;
+    int number2 = 1051;
+
+    // when
+    boolean actual = bcCryptWorkFactorService.isPreviousDurationCloserToGoal(number1, number2);
+
+    // then
+    assertThat(actual).isTrue();
+  }
+
+  @Test
+  void findCloserToShouldReturnNUmber2IfItCloserToGoalThanNumber1() {
+    // given
+    int number1 = 1002;
+    int number2 = 999;
+
+    // when
+    boolean actual = bcCryptWorkFactorService.isPreviousDurationCloserToGoal(number1, number2);
+
+    // then
+    assertThat(actual).isFalse();
+  }
+
+  @Test
+  void findCloserToShouldReturnGoalIfNumber2IsEqualGoal() {
+    // given
+    int number1 = 999;
+    int number2 = 1000;
+
+    // when
+    boolean actual = bcCryptWorkFactorService.isPreviousDurationCloserToGoal(number1, number2);
+
+    // then
+    assertThat(actual).isFalse();
+  }
+
+  @Test
+  void findCloserToShouldReturnGoalIfNumber1IsEqualGoal() {
+    // given
+    int number1 = 1000;
+    int number2 = 1001;
+
+    // when
+    boolean actual = bcCryptWorkFactorService.isPreviousDurationCloserToGoal(number1, number2);
+
+    // then
+    assertThat(actual).isTrue();
+  }
+
+  @Test
+  void getStrengthShouldReturn4IfStrengthIs4() {
+    // given
+    int currentStrength = 4;
+
+    // when
+    int actual = bcCryptWorkFactorService.getStrength(0, 0, currentStrength);
+
+    // then
+    assertThat(actual).isEqualTo(4);
+  }
+
+  @Test
+  void getStrengthShouldReturnPreviousStrengthIfPreviousDurationCloserToGoal() {
+    // given
+
+    // when
+    int actual = bcCryptWorkFactorService.getStrength(980, 1021, 5);
+
+    // then
+    assertThat(actual).isEqualTo(4);
+  }
+
+  @Test
+  void getStrengthShouldReturnCurrentStrengthIfCurrentDurationCloserToGoal() {
+    // given
+
+    // when
+    int actual = bcCryptWorkFactorService.getStrength(960, 1021, 5);
+
+    // then
+    assertThat(actual).isEqualTo(5);
+  }
+}
diff --git a/spring-boot/password-encoding/src/test/java/io/reflectoring/passwordencoding/workfactor/Pbkdf2WorkFactorServiceTest.java b/spring-boot/password-encoding/src/test/java/io/reflectoring/passwordencoding/workfactor/Pbkdf2WorkFactorServiceTest.java
new file mode 100644
index 0000000..c0b2a59
--- /dev/null
+++ b/spring-boot/password-encoding/src/test/java/io/reflectoring/passwordencoding/workfactor/Pbkdf2WorkFactorServiceTest.java
@@ -0,0 +1,21 @@
+package io.reflectoring.passwordencoding.workfactor;
+
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.AssertionsForClassTypes.assertThat;
+
+class Pbkdf2WorkFactorServiceTest {
+
+  private Pbkdf2WorkFactorService pbkdf2WorkFactorService = new Pbkdf2WorkFactorService();
+
+  @Test
+  void calculateIteration() {
+    // given
+
+    // when
+    int iterationNumber = pbkdf2WorkFactorService.calculateIteration();
+
+    // then
+    assertThat(iterationNumber).isGreaterThanOrEqualTo(150000);
+  }
+}