The present invention provides processes by which fatigue testing can be carried out by altering the vibrational characteristics of a component, but without physically altering the component itself. Subsequently, the pretreated titaniferous material is leached under acid conditions, causing the silica to enter solution under conditions such that the silica is not hydrolysed or precipitated as a silicate. Accordingly, when verification data is received, if the verification data is not conform with the original data, the verification process will not be successful. A valid link is determined from the trellis by some dictionary word traversing the link.