Since you haven’t posted any code, it’s difficult to know exactly which problems you’re encountering. However, the blog post you link to does seem to work pretty decently… aside from the extra comma in each call to CCCrypt() which caused compile errors. A later comment on that post includes this adapted code, which works for … Read more
If you just want to use the built-in crypto provider RijndaelManaged, check out the following help article (it also has a simple code sample): http://msdn.microsoft.com/en-us/library/system.security.cryptography.rijndaelmanaged.aspx And just in case you need the sample in a hurry, here it is in all its plagiarized glory: using System; using System.IO; using System.Security.Cryptography; namespace RijndaelManaged_Example { class RijndaelExample … Read more
Share the password (a char[]) and salt (a byte[]—8 bytes selected by a SecureRandom makes a good salt—which doesn’t need to be kept secret) with the recipient out-of-band. Then to derive a good key from this information: /* Derive the key, given password and salt. */ SecretKeyFactory factory = SecretKeyFactory.getInstance(“PBKDF2WithHmacSHA256”); KeySpec spec = new PBEKeySpec(password, … Read more