Inner Circle uses AES-256 bit encryption which can be used to encrypt files or text messages. Encrypted data is stored as a Base64 ASCII encoded data. It is meant to encrypt small files and messages as the methods load all file data to memory before processing it.
To encrypt files you first select a file to be encrypted and write a passprase and then click the "Encrypt file" button. This generates file in the same direcory with a ".encrypted" extension. The files can be decrypted similarly by selecting crypted file, writing a passphrase and by clicking the "Decrypt file" button.
To encrypt messages you first write a passphrase and then select the "Encrypt message.." button. This will generate ASCII encoded block of data into the message box which can be cut'n'pasted and send over insecure channel to the recipient. To decrypt message write the passphrase and select the "Decrypt message.." button. Then cut'n'paste ASCII data block into the window and decipher the message.
The software extends secure AES-256 bit encryption by using it twice to data. This means there are two 256 bit keys which are created using the SHA 512 bit message digest of a passphrase. Encrypted data is also compressed before processing it through encryption algorithms.