Work with strings

function StringEncrypter( encryptionScheme:String, encryptionKey:String ){

  try{

    encryptionScheme = encryptionScheme || this.DESEDE_ENCRYPTION_SCHEME;

    encryptionKey = encryptionKey || this.DEFAULT_ENCRYPTION_KEY;

    if( encryptionKey.length < 24 ){ 

      throw new java.lang.Exception( 

        'Encryption key was less than 24 characters.' ); 

    }

    var keyAsBytes = encryptionKey.getBytes( this.UNICODE_FORMAT );

    switch( encryptionScheme ){

      case this.DESEDE_ENCRYPTION_SCHEME: 

        this.keySpec = new javax.crypto.spec.DESedeKeySpec( keyAsBytes ); break;

      case this.DES_ENCRYPTION_SCHEME: 

        this.keySpec = new javax.crypto.spec.DESKeySpec( keyAsBytes ); break;

      default: 

        throw new java.lang.Exception( 

          "Encryption scheme not supported: "  + encryptionScheme );

    }

    this.keyFactory = javax.crypto.SecretKeyFactory.getInstance( encryptionScheme );

    this.cipher = javax.crypto.Cipher.getInstance( encryptionScheme );

  } catch( e ){ /* your exception handling */ }

}

StringEncrypter.prototype = {

  DESEDE_ENCRYPTION_SCHEME: "DESede",

  DES_ENCRYPTION_SCHEME: "DES",

  DEFAULT_ENCRYPTION_KEY: 

    "The ships hung in the sky in much the same way that bricks don't.",

  UNICODE_FORMAT: "UTF8",

  keySpec: null,

  keyFactory: null,

  cipher: null,

  encrypt: function( unencryptedString ){

    if( !unencryptedString ){ return ''; }

    try {

      var key = this.keyFactory.generateSecret( this.keySpec );

      this.cipher.init( javax.crypto.Cipher.ENCRYPT_MODE, key );

      var clearText = unencryptedString.getBytes( this.UNICODE_FORMAT );

      var cipherText = this.cipher.doFinal( clearText );

      var base64encoder = new sun.misc.BASE64Encoder();

      return base64encoder.encode( cipherText );

    } catch( e ){ /* your exception handling */ }

  },

  decrypt: function( encryptedString ){

    if( !encryptedString ){ return ''; }

    try {

      var key = this.keyFactory.generateSecret( this.keySpec );

      this.cipher.init( javax.crypto.Cipher.DECRYPT_MODE, key );

      var base64decoder = new sun.misc.BASE64Decoder();

      var clearText = base64decoder.decodeBuffer( encryptedString );

      var cipherText = this.cipher.doFinal( clearText );

      return new java.lang.String( cipherText );

    } catch( e ){ /* your exception handling */ }

  }

}

var encrypter = new StringEncrypter();

encrypter.encrypt( unencryptedString );

var encrypter = new StringEncrypter();

encrypter.decrypt( encryptedString );