What is Hashing? How Customer Data Is Sent Safely
Also known as: hash, SHA-256, one-way code
Short answer
Hashing turns a value into a fixed string of letters and digits that cannot be reversed back to the original. The same value always produces the same code, so two parties can compare codes without exchanging the underlying data.
Example
The email `budi@example.com` becomes a long code that is always identical. The ad platform compares that code against codes from its own user data.
The simple way to think about it
Picture a grinder. You put in coffee beans and powder comes out. The same beans always give the same powder, but you cannot turn powder back into beans.
Because the same beans always give identical powder, two people can prove they hold the same beans without ever showing each other the beans.
The rules people break most
| Wrong | Right |
|---|---|
| Sending raw email | Sending a one-way code of a normalised email |
| Sending values encrypted by your own system | Sending a standard one-way code |
| Hashing before normalising | Normalise the format, then hash |
| Hashing a phone with plus signs and spaces | Digits with a country code only, then hash |
Frequently asked questions
- What is the difference between hashing and encryption?
- Encryption can be undone with a key; hashing cannot be reversed. Sending identifiers to ad platforms uses standard hashing, never encryption. Ciphertext will not match anything on their side.
- Why must values be normalised before hashing?
- Because hashing is extremely sensitive. One capital letter or one space produces a completely different code. Normalising makes sure both sides compute the code from identical values.
- Does hashing make customer data completely safe?
- Hashing removes the ability to read the original value, but the same code can still recognise the same person. So send only the data you genuinely need, and keep a lawful basis for using it.
Related terms
Your ad numbers are only as accurate as the data behind them
Konektor captures the Click ID and sends conversions that close on WhatsApp, over the phone, or in a shop back to the ad platform.