The canonical wisdom is that the more security sensitive or critical a piece of software is, the more important it is that it be auditable. Open Source meets th

The canonical wisdom is that the more security sensitive or critical a piece of software is, the more important it is that it be auditable. Open Source meets that criterium, and is arguably the only thing that does so fully. Some systems do require secrets, that's what cryptography is for. The algorithms are generally open and audited, and only the minimum (the keys) are kept secret.