README.md in symmetric-encryption-1.0.0 vs README.md in symmetric-encryption-1.1.1

@@ -10,10 +10,13 @@
 in configuration files have to be encrypted
 
 This Gem helps achieve compliance by supporting encryption of data in a simple
 and consistent way
 
+Symmetric Encryption uses OpenSSL to encrypt and decrypt data, and can therefore
+expose all the encryption algorithms supported by OpenSSL.
+
 ## Security
 
 Many solutions that encrypt data require the encryption keys to be stored in the
 applications source code or leave it up to the developer to secure the keys on
 the application servers. symmetric-encryption takes care of securing the
@@ -236,9 +239,28 @@
 
     rake symmetric_encryption:encrypt
 
 Note: Passwords must be encrypted in the environment in which they will be used.
   Since each environment should have its own symmetric encryption keys
+
+Encrypt a file
+
+    INFILE="Gemfile.lock" OUTFILE="Gemfile.lock.encrypted" rake symmetric_encryption:encrypt_file
+
+Encrypt and compress a file
+
+    INFILE="Gemfile.lock" OUTFILE="Gemfile.lock.encrypted" COMPRESS=1 rake symmetric_encryption:encrypt_file
+
+Decrypt a file encrypted and optionally compressed using symmetric encryption
+
+    INFILE="Gemfile.lock.encrypted" OUTFILE="Gemfile.lock2" rake symmetric_encryption:decrypt_file
+
+When decrypting a compressed file it is not necessary to specify whether the file was compressed
+since the header embedded in the file will indicate whether it was compressed
+
+The file header also contains a random key and iv used to encrypt the files contents.
+The key and iv is encrypted with the global encryption key being used by the symmetric
+encryption installation.
 
 ## Installation
 
 ### Add to an existing Rails project
 Add the following line to Gemfile