Module pin 

PIN-based encryption for identity keys.

Encrypts signing, recipient, and (optionally) Nostr secret keys using:

• Argon2id for PIN → key derivation (memory-hard, resistant to brute force)
• AES-256-GCM for authenticated encryption

Format versions

v1 (legacy): [1B version=1][16B salt][12B nonce][64B encrypted][16B tag]

• Payload: 32B signing + 32B recipient = 64 bytes

v2 (current): [1B version=2][16B salt][12B nonce][96B encrypted][16B tag]

• Payload: 32B signing + 32B recipient + 32B nostr = 96 bytes

Decryption is backward-compatible: v1 blobs return nostr = None.

Enums

PinError

Errors during PIN encryption/decryption.

Functions

decrypt_identity_keys

Decrypt identity keys using a PIN.

encrypt_identity_keys

Encrypt signing, recipient, and Nostr keys using a PIN (v2 format).