SecondFi Offers 30 ADA Per Unrecoverable NFT After $21M Cardano (ADA) Hack
Key Takeaways
- •A June 2026 defect in how SecondFi's Cardano wallets derived nonce values exposed users' private keys.
- •Assets valued at roughly $21 million were compromised in the resulting hack.
- •SecondFi is offering 30 ADA in compensation for each NFT that cannot be recovered.
- •The flaw was located in SecondFi's wallet key-handling code rather than in the Cardano network itself.
- •The published report does not specify how affected users can submit claims or how unrecoverable status will be verified.
A flaw in the key-handling code of SecondFi's crypto wallets for Cardano (ADA) set the incident in motion. In June 2026, a defect in how the wallets derived nonce values — the single-use numbers used in every transaction signature — left users' private keys exposed, and assets worth roughly $21 million were compromised in the resulting hack.
In response, SecondFi is offering 30 ADA for each non-fungible token (NFT) that cannot be recovered.
SecondFi provides crypto wallets built for the Cardano network, the proof-of-stake blockchain whose native token is ADA. The June 2026 defect concerned nonce derivation, a core step in transaction signing. In digital signature schemes, a nonce is a single-use number incorporated into every signature; when nonces are predictable, reused, or incorrectly derived, they can allow an attacker to reconstruct the underlying private keys. Flawed nonce generation is a well-documented class of cryptographic vulnerability, and past incidents across the industry have shown that weak randomness in signing can lead directly to key exposure and loss of funds. Notably, the defect here was located in the wallet's key-handling code rather than in the Cardano network itself — a reminder that wallet-side implementation errors can expose user funds even when the blockchain protocol is not the point of failure.
In this case, the improperly derived nonces left users' private keys exposed, and assets valued at approximately $21 million were affected.
Under the compensation offer, affected users whose NFTs are unrecoverable are eligible to receive 30 ADA per token. The published report does not specify how affected users can submit claims or how an NFT's unrecoverable status will be determined — details that would shape how the 30 ADA offer is applied in practice.
Cardano (ADA) is a proof-of-stake blockchain platform, and NFTs on the network are issued as native assets recorded directly on the chain.
This content was first published on COINOTAG: https://en.coinotag.com/secondfi-offers-30-ada-per-unrecoverable-nft-cardano-hack
