What is the role of hash functions in timestamping?
Hash functions are the most important cryptographic functions involved in timestamping. They provide a one-way causal relationship between timestamped data and timestamps. During every second, the GuardTime system collects timestamp requests from all over the world and creates a single 256-bit hash code by using a cryptographic hash function. Every month, the per-second hash codes are again hashed together into a 256-bit hash code which is then published in newspapers.
