Hi Walter,

>The RC4 encryption algorithm is extremely fast and is considered safe.

Yep, speed depends on a lot of factors. With RC4, for instance, speed and security depend on the key length. There's an RC4 specification with 40 bits that considered insecure today because it has been broken by a brute-force attack. Longer keys are still considered secure. However, RC4 is a stream cipher. I'd always go with a block cipher, even if it's a bit slower. An upcoming Advisor article will explain why. <s>