There have been so many incidents in crypto that exploited broken assumptions about hash collisions. Factually, X != hash(X). Sometimes you can make the simpli

There have been so many incidents in crypto that exploited broken assumptions about hash collisions. Factually, X != hash(X). Sometimes you can make the simplifying assumption that X == hash(X), but only in well-defined contexts, subject to proper risk analysis; never in general, or as a presumption of a system that needs to be correct.