保护Spring Data Rest的数据可以通过以下几种方法来实现：

1. 使用Spring Security进行身份验证和授权： 首先，确保已在项目中添加Spring Security依赖。然后可以使用Spring Security的配置来保护Spring Data Rest的数据。以下是一个示例代码：

@Configuration
@EnableWebSecurity
public class SecurityConfig extends WebSecurityConfigurerAdapter {

    @Autowired
    private UserRepository userRepository;

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http
            .authorizeRequests()
                .antMatchers("/api/**").authenticated()
                .anyRequest().permitAll()
                .and()
            .httpBasic().realmName("My Realm")
                .and()
            .csrf().disable();
    }

    @Override
    protected void configure(AuthenticationManagerBuilder auth) throws Exception {
        auth.userDetailsService(userDetailsService());
    }

    @Bean
    public UserDetailsService userDetailsService() {
        return new UserDetailsService() {
            @Override
            public UserDetails loadUserByUsername(String username) throws UsernameNotFoundException {
                User user = userRepository.findByUsername(username);
                if (user == null) {
                    throw new UsernameNotFoundException("User not found");
                }
                return user;
            }
        };
    }
}

在该示例中，配置了一个安全规则，只允许经过身份验证的用户访问/api/**路径下的资源，其他路径则允许匿名访问。通过UserRepository获取用户信息，并使用UserDetailsService进行身份验证。

2. 自定义访问权限控制： 可以在Spring Data Rest的资源类中使用注解来控制访问权限。以下是一个示例代码：

@RepositoryRestResource
@PreAuthorize("hasRole('ROLE_ADMIN')")
public interface UserRepository extends JpaRepository {
    // ...
}

在该示例中，使用@PreAuthorize注解来指定只有拥有ROLE_ADMIN角色的用户才能访问该资源。

3. 使用HTTPS进行数据传输保护： 可以配置Spring Boot应用程序使用HTTPS协议来保护数据传输。以下是一个示例配置代码：

@Configuration
public class SecurityConfig {

    @Value("${server.port}")
    private int serverPort;

    @Value("${server.ssl.key-store}")
    private String keyStorePath;

    @Value("${server.ssl.key-store-password}")
    private String keyStorePassword;

    @Bean
    public ServletWebServerFactory servletContainer() {
        TomcatServletWebServerFactory tomcat = new TomcatServletWebServerFactory() {
            @Override
            protected void postProcessContext(Context context) {
                SecurityConstraint securityConstraint = new SecurityConstraint();
                securityConstraint.setUserConstraint("CONFIDENTIAL");
                SecurityCollection collection = new SecurityCollection();
                collection.addPattern("/*");
                securityConstraint.addCollection(collection);
                context.addConstraint(securityConstraint);
            }
        };
        tomcat.addAdditionalTomcatConnectors(createHttpConnector());
        return tomcat;
    }

    private Connector createHttpConnector() {
        Connector connector = new Connector(TomcatServletWebServerFactory.DEFAULT_PROTOCOL);
        connector.setScheme("http");
        connector.setPort(8080);
        connector.setSecure(false);
        connector.setRedirectPort(serverPort);
        return connector;
    }

    @Bean
    public TomcatServletWebServerFactory tomcatEmbeddedServletContainerFactory() {
        TomcatServletWebServerFactory tomcat = new TomcatServletWebServerFactory();
        tomcat.addAdditionalTomcatConnectors(redirectConnector());
        return tomcat;
    }

    private Connector redirectConnector() {
        Connector connector = new Connector("org.apache.coyote.http11.Http11NioProtocol");
        connector.setScheme("http");
        connector.setPort(8080);
        connector.setSecure(false);
        connector.setRedirectPort(serverPort);
        return connector;
    }

    @Bean
    public EmbeddedServletContainerFactory servletContainerFactory() {
        TomcatEmbeddedServletContainerFactory factory = new TomcatEmbeddedServletContainerFactory();
        factory.addAdditionalTomcatConnectors(httpConnector());
        return factory;
    }

    private Connector httpConnector() {
        Connector connector = new Connector("org.apache.coyote.http11.Http11NioProtocol");
        connector.setScheme("http");
        connector.setPort(8080);
        connector.setSecure(false);
        connector.setRedirectPort(serverPort);
        return connector;
    }

    @Bean
    public EmbeddedServletContainerCustomizer embeddedServletContainerCustomizer() {
        return (container -> {