Xceed .NET Libraries Documentation
EncryptionMethod Enumeration


Xceed.Zip Assembly > Xceed.Zip Namespace : EncryptionMethod Enumeration
Encryption method to use to encrypt a file when an encryption password is provided, or encryption method detected when reading an encrypted file.
Syntax
'Declaration
 
Public Enum EncryptionMethod 
   Inherits System.Enum
   Implements System.IComparableSystem.IConvertibleSystem.IFormattable 
'Usage
 
Dim instance As EncryptionMethod
Members
MemberValueDescription
Compatible1The traditional ZIP encryption. This is a weak encryption method.
WinZipAes2The WinZip AES encryption method. This is a strong encryption method.
Remarks

The Compatible encryption method is considered weak by today's standards and its use is recommended only for situations with low security needs or for compatibility with older zip archives.

When decrypting data using Compatible encryption, the password verification isn't 100% accurate. It is possible that an invalid password will not be detected. In that case, decryption will process but the decrypted data will be garbage. In the context of unzipping, this will always result in a decompression failure or a checksum failure so no incorrect data will ever be delivered. However, special care needs to be taken when handling exceptions.

For WinZipAES, AES stands for Advanced Encryption Standard. It is a specification for the encryption of electronic data established by the U.S. National Institute of Standards and Technology. It specifies a set of specific key and block sizes on the Rijndael cipher. As of 2013, no attacks of the encryption that are computationally faster than a full brute force attack are known.

WinZip is part of the name because the encrypted data is framed using a format called 'counter mode' that was first implemented by the WinZip application.

Example
Unzipping encrypted items that use 'compatible' encryption
Inheritance Hierarchy

System.Object
   System.ValueType
      System.Enum
         Xceed.Zip.EncryptionMethod

Requirements

Target Platforms: Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

See Also

Reference

Xceed.Zip Namespace

Creating secure passwords

Strong passwords: How to create and use them
Create secure password or login

General information

Compatible Encryption specification (see Section VII)
Advanced Encryption Standard (AES)
WinZipAES specification