When files are transferred via Internet or local area network they can be intercepted and read by a stranger. Use this extension to protect them from the unauthorized access. The following encryption algorithms can be used:

Blowfish is a symmetric block cipher with key lengths from 32 bits to 128 bits with the block length 64 bits. The algorithm is patent, royalty and license free. Blowfish has been extensively analyzed and it is acknowledged as a strong cipher.

DES (Data Encryption Standard) algorithm was the first encryption standard. DES is a symmetric block cipher. The key length is usually quoted as 64 bits, but in reality only 56 bits of these 64 participate in the encryption algorithm. DES was extensively analyzed and is now accepted to be a strong algorithm, except for one area: the key length. A 56-bit key is within the reach of brute-force attacks using a network of high-powered machines. DES should therefore only be used for temporary data; data that would be out-of-date before someone brute-force cracked an encrypted message.

Since DES’s 56-bit key is too short to counter brute-force attacks, several modifications to the DES standard have been proposed in order to strengthen it. The most successful of these is the Triple-DES algorithm. Triple-DES is three times slower than DES however the cipher is much more secure than simple DES. It uses two keys as a single 128-bit value and follows the encrypt-decrypt-encrypt process with blocks 64 bits long.

AES (Advanced Encryption Standard) is the replacement for the Data Encryption Standard (DES). It is a symmetric block cipher with variable key lengths and block sizes. It supports 128, 192, and 256-bit keys and 128-bit blocks.

If it is used together with File compression extension it allows to password-encrypt the transmitted files. This makes a transfer of files on networks considerably safer. The files can be decrypted by the recipient using any ZIP decompression program, such as WinZip, PKWare pkzip etc.

Some countries restrict application of software that uses strong encryption. If you intend this extension using we strongly advise you to find out what your country's laws allow or restrict.