From Chilkat Software:
The ChilkatZip Self-Extractor can safely encrypt the contents of your ZIP file with 128, 192, or 256-bit AES Encryption. To unzip, a user must provide the same password that was used when creating the self-extracting EXE. AES encryption is much stronger than standard ZIP encryption, which is regarded by security experts as being insecure. Chilkat's streaming compression and encryption technology allows the ChilkatZip Self-Extractor to create an EXE from any size ZIP file. The streaming compression and decryption technology also ensures that it will be possible to unzip the archive on your end-user's computer, even if that computer has very little memory. A progress bar is displayed during the unzip process so your end-user can decide whether there is time to get a cup of coffee while his computer is unzipping an especially large ZIP file.