I've been having a really hard time figuring out how to store a Secp256k1 privateKey from multiple libraries (currently on this one for ECIES encryption: https://npm.io/package/@toruslabs/eccrypto).
I have tried encoding and decoding with base64, many implementations of functions that copy array buffer for input encoded string to localStoarge and corresponding output Uint8Array from localStorage, I tried it with IndexedDB, JSON.stringify and parse do not work with binary data, and so many more variations.
When I go through the array buffer elements individually to copy it into a new Uint8Array, I get a similar private key, but with two missing key/field's (parent and offset) which I believe is why every library I have tried so far returns something a long the lines of "bad private key" when I try generating the public key from them.
I am exhausted and I would like some professional insight for my lack of skill in this particular subject. So how can I store (in any way as long as it's client/local) a Secp256k1 private key in a way that if I call it from that persistent client sided data base, they can be used to generate the public keys?