assertNotNull(cryptographer);

        String plainText = "Hello, World!";
        String encrypted = cryptographer.encrypt(plainText);
        assertNotNull(encrypted);
        assertFalse(plainText.equals(encrypted));

        String decrypted = cryptographer.decrypt(encrypted);
        assertEquals(plainText, decrypted);
    }

    public void test_invertibleCryptography_withEmptyString() {

            @Override
            public String encrypt(String plainText) {
                return "encrypted:" + plainText;
            }

            @Override
            public String decrypt(String cryptedText) {
                return cryptedText.startsWith("encrypted:") ? cryptedText.substring("encrypted:".length()) : cryptedText;
            }
        };

        deleteUserCodeFromCookie(request);
        return userCode;
    }

    /**
     * Creates an encrypted user code from a user ID.
     * The user ID is encrypted using the primary cipher and validated against the configuration.
     *
     * @param userCode the raw user ID to encrypt
     * @return the encrypted and validated user code, or null if invalid
     */
    protected String createUserCodeFromUserId(String userCode) {

- **Concurrent Utilities** (`org.codelibs.core.concurrent`) - Thread-safe collections and concurrency helpers using modern concurrent APIs
- **Crypto & Security** (`org.codelibs.core.crypto`, `org.codelibs.core.security`) - Basic cryptographic utilities, message digest operations, and secure random generation

        if (logger.isDebugEnabled()) {
            logger.debug("system.properties: {}", value);
        }
        if (StringUtil.isNotBlank(value)) {
            ParameterUtil.parse(ParameterUtil.encrypt(value)).entrySet().stream().filter(e -> {
                final String key = e.getKey();
                if (StringUtil.isBlank(key)) {
                    return false;
                }

    }

    default void setLdapAdminSecurityCredentials(final String value) {
        setSystemProperty(Constants.LDAP_ADMIN_SECURITY_CREDENTIALS,
                Constants.CIPHER_PREFIX + ComponentUtil.getPrimaryCipher().encrypt(value));
    }

    default String getLdapAdminSecurityCredentials() {
        final String value = getSystemProperty(Constants.LDAP_ADMIN_SECURITY_CREDENTIALS);

   * 1-bit characteristics.
   *
   * <p>There is more general code provided by Bob Jenkins to test arbitrarily sized characteristics
   * using the magic of gaussian elimination: http://burtleburtle.net/bob/crypto/findingc.html.
   */
  static void checkNo2BitCharacteristics(HashFunction function) {
    Random rand = new Random(0);
    int keyBits = 32;

    // get every one of (keyBits choose 2) deltas:

import java.util.Collections;
import java.util.Iterator;
import java.util.List;
import java.util.zip.Adler32;
import java.util.zip.CRC32;
import java.util.zip.CRC32C;
import java.util.zip.Checksum;
import javax.crypto.spec.SecretKeySpec;
import org.jspecify.annotations.Nullable;

/**
 * Static methods to obtain {@link HashFunction} instances, and other static hashing-related
 * utilities.
 *

- Included an additional resource labeltransformation in on_operations_total metric which could be used for resource specific validations for example handling of encryption config by the apiserver. ([#126512](https://github.com/kubernetes/kubernetes/pull/126512), [@kmala](https://github.com/kmala)) [SIG API Machinery, Auth, Etcd and Testing]

- Kube-apiserver: the `--encryption-provider-config` file is now loaded with strict deserialization, which fails if the config file contains duplicate or unknown fields. This protects against accidentally running with config files that are malformed, mis-indented, or have typos in field names, and getting unexpected behavior. When `--encryption-provider-config-automatic-reload` is used, new encryption config files that contain typos after the kube-apiserver is running...