TinkerThe invoice and its SHA-256 fingerprint.In the open: HASH f0ec1110
Chapter 5 of 7
A fingerprint
The toy seal signed one number made from the whole invoice. That number is a fingerprint.
This chapter: What is a hash, and why does one changed character change all of it?
About this chapter
You will learn
- A hash is a short fingerprint of any message
- One changed character flips about half its bits
- You can’t run a hash backwards
Words you’ll meet
- Hash
- A fixed-size fingerprint of any message; the same message always gives the same one.
- SHA-256
- A hash whose fingerprint is 256 bits, written as 64 hex characters.
Step 1 of 3
A is a fingerprint: turns the whole invoice into 64 hex characters. Signatures sign it.
Predict what one changed digit does.
SHA-256 of “Invoice 1207: pay 1880.00 to account 4417-2209.”f0ec1110d26513fa28a45aff3ebd97ae89966b7d594bc88d9aa479611506d7de