How do you migrate legacy password hashes?
PICTURE THIS: HASH MAP
Simple meaning
On successful login with old algorithm, rehash with Identity hasher and store.
WHY — Identity instead of guessing?
Why interviewers care about Identity:
question about Identity.
trade-offs, and what you would actually do on a .NET MVC project - not buzzwords.
Name the idea, why it exists, then one short example.
End with when you use it and one common pitfall.
STEPS — What happens step by step?
Before you speak the answer, walk the interviewer through these steps:
- 1On successful login with
old algorithm, rehash with Identity hasher and store.
- 2Why it exists
Users upgrade transparently.
- 3Force reset if algorithm
is too weak.
- 4Give an example
One tiny concrete case you can say aloud.
- 5Common mistake
What juniors usually get wrong.
- 6Close
When you pick this over the alternative.
EXAMPLE — See it in action
Here's a short line you can speak, broken into clear beats:
Note: Adapt this scaffold to your own project — keep it under 60–90 seconds.
Key takeaway
On successful login with old algorithm, rehash with Identity hasher and store. Users upgrade transparently.