How can I make my AES encryption identical between Java and Objective-C (iPhone)?

Question

I am encrypting a string in objective-c and also encrypting the same string in Java using AES and am seeing some strange issues. The first part of the result matches up to a

Answer 1

Just to add to the first post: in your objective C/cocoa code you used CBC mode and in your java code you used EBC and an IV initialization vector wasn't used in either. EBC cipher is block by block and CBC chains upon the preceding block, so if your text is smaller than 1 block (=16 bytes in your example), the cipher text produced by both are decryptable by the other (the same).

If you are looking for a way to standardize your use of the ciphers, NIST Special Publication 800-38A, 2001 Edition has test vectors. I can post code for the AES CBC and EBC vectors if it's helpful to anyone.