Question

So, how do I do it? Can’t find any example anywhere that successfully uses RC4.
Also, doing cipher = Cipher.getInstance(“RC4”); returns a NoSuchAlgorithm exception

Answer 1

If you list the available Ciphers:

    Provider[] providers = Security.getProviders();
    for (Provider provider : providers) {
        for (Object entry : provider.keySet()) {
            String name = String.valueOf(entry);
            if (name.startsWith("Cipher")) {
                Log.d("Cipher", "Supports: " + name.substring(7));
            }
        }
    }

There’s a few RC4 variants – such as PBEWITHSHAAND128BITRC4 (PKCS#5). Which one do you need?