What is CBC?
When changing the key (click here to learn to change the key), CRFSuite asks if you would like to use CBC encryption mode.
CBC is a powerful mode of using the encryption algorithms. Using AES with CBC data generated looks pseudo-random and cannot be understood without the encryption key. This encryption mode is supported by CRFSuite 3.1 and above. A .CRF file encrypted with CBC mode will not be decoded by previous versions of CRFSuite.
In the example below, we have encrypted a picture using ECB and CBC:
|Original image||Encrypted using old method (ECB mode)||Encrypted using new method (CBC mode)|
Please note that the data encrypted by the reader is quite small therefore it will not generate a pattern like in the above picture. For this reason is almost impossible to decrypt it without a key even if it is encrypted with old mode (ECB). However it will be even more difficult to crack it with the new encryption mode (CBC).