1. A method, comprising: operating a memory device, which comprises a memory and a memory controller that connects the memory to an unsecure link, in accordance with a secure testing mode in which the memory device is allowed to expose on the unsecured link only information from which data stored in the memory cannot be deduced; while operating in accordance with the secure testing mode, reading one or more words from the memory using the memory controller; calculating using the memory controller a result of a one-way function applied to the one or more words, such that none of the one or more words can be recovered from the result; and outputting from the memory device, on the unsecure link, encoded information indicative of errors occurring in the one or more words, based on the calculated result.