This is a very simple example of a nonce calculation done with sha1 hashing algorithm in PHP

Prerequisites:

• Knowledge of the concepts: "nonce" calculation, "proof of work," and basic PHP programming skills.

1. A 256 character-long random string is generated with a simple function called d256()
2. The string is hashed in sha1
3. An incremented integer is concatenated to the original hash in a loop until the desired "proof of work" difficulty is successfully calculated as a new sha1 hash.