Presigning is a technique of allowing failsafe access to funds in the event of private key loss.
When presigning is enabled on select accounts, the Coincast app may prompt the user for their PIN to secure their funds. Once the wallet's private key is generated via the PIN, the app will generate signed transactions which, if broadcast to the blockchain, would move the wallet's balance into the secured Coincast cold storage wallet. These signed transactions are not broadcast. However, instead they are asymmetrically encrypted and stored on our servers, they can only be decrypted via an offline private key.
In the event of PIN loss, funds become permanently lost. However, if the wallet was presigned, Coincast may then be able to assist in fund recovery by broadcasting the presigned transaction to the blockchain and moving the funds out of the lost wallet and into Coincast's cold storage wallet. This would be vary rarely executed, if ever, and would be publicly visible on the blockchain for all to witness.
Yes, most accounts by default are not eligible for presigning. Accounts with larger balances may be prompted to "secure their funds" which is one example of when presigning occurs. If you wish to opt out of these protections fully, simply go to your profile page and you can opt out from there.
We are not responsible for any fund loss. We reserve the right to invoke the broadcasting of presigned transactions, with the intent of helping one recover their funds, at our sole discretion. We may not invoke presign broadcasting at will. We recommend all users always keep a written copy of their private keys (accessible from the app's hamburger menu) stored in a secure and safe place, so that they can access funds in the event of loss of access to one's wallet.