Pattern 74: Paranoid security
AKA: Big brother

Naturally, You are concerned about SECURITY AND ENCRYPTION (72). You have CLASSIFIED YOUR SITE (11).

Companies want to be sure that their customers are who they say they are. Customers want privacy and find elaborate dialogues irritating. How can these forces be balanced? How do you authenticate a visitor without trampling on their privacy?

Therefore

Base security measures on a thorough risk analysis. Relate security measures to your business objectives. Trade off security measures against well thought out recovery procedures – and don’t forget that the best security can be bypassed by the determined. Only use authentication technique when it is absolutely necessary. Don’t frighten users with unnecessary warnings.

This antipattern is terminal within this language.

The amount of security that a site requires varies according to the business of the site. An appropriate analogy is the security of buildings. Banks are usually harder to break into than carpet warehouses. Homes containing valuables are often better protected than the homes of the poor. People trade off the cost of burglar alarms and barred windows against the cost of recovery strategies like household insurance. In some districts even the poor have to protect their homes against the risk of violence and malicious damage.
In the context of the web there are a range of types of site with varying security needs. At one extreme there are hobby sites that are unlikely to be hacked and on which there is really nothing to steal. One level up from this we might consider an academic’s site containing résumés and publications. The academic would be unhappy if someone downloaded a paper and altered it or claimed to have written it. In fact, recently there have been muttering in academe about students populating their essays with words in this way. The common solution is to publish material in some uneditable format such as PDF.

Commercial sites need to take more care. The user should be able to verify that the site is really the one it claims to be before entering credit card details. The common solution is to use a trusted third party such as Verisign to provide this confidence. Commercial transaction may need to be encrypted. Banking sites have even stronger requirements.

Problems only arise when the degree of security outweighs the need for it. Enforced registration or authentication dialogues will deter the casual (but harmless) browser and may cost sales. Messages that highlight the risks to the user can frighten people away only too easily. Only display warnings when they tell the user something that they really need to know.

Example
The author’s trireme.com emails are visible to some of his colleagues. He therefore wants purchase confirmations to go to his private email address (which he accesses using a non-web-aware program). When he tries to buy from some sites having logged on as ian@trireme.com, he is asked to type his address. He enters his other (CompuServe) address. The site rejects his form. They loose his business. Amazon lets him do this, so why can this site? It’s pure paranoeia.

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