Cognitive and cultural embeddedness: combining institutional economics and economic sociology
According to this, pederasty is sexual relations between two males, especially when one of them is a minor. Other definitions, like the one that JSBangs found, differ slightly. But otherwise, I think you answered the question yourself: pedophile refers to the attraction, while pederasty refers to the act itself.
Noun. 1. pederast-a man who has sex (usually sodomy) with a boy as the passive partner. child molester, paederast. degenerate, deviant, deviate, pervert-a person whose behavior deviates from what is acceptable especially in sexual behavior. Translations.