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TR-31 / X9.143 key block builder & parser
Wrap a key in a real TR-31 key block (versions A, B, C, or D), see the derived encryption and MAC keys, then parse it back, or relabel its key usage and watch the MAC reject the swap.
What's happening under the hood →·Read the Password hashing & key derivation: PBKDF2, bcrypt, scrypt, Argon2 module for the full explanation →·See the Key wrapping and key exchange: moving keys without ever exposing them use case →·See the PIN blocks: encrypting a 4-digit number like it's a nuclear launch code use case →·See the DUKPT: a fresh key for every card payment at the counter use case →·See the Key ceremonies and the HSM key hierarchy: where every payment key comes from use case →
1. Build a key block
2. Parse and verify a key block