Tangem technology allows private key backups using authentication devices like cards or rings, employing cryptographic techniques.
The United States has awarded Tangem a patent for its private key preservation technology. According to official records, the United States Patent and Trademark Office (USPTO) granted a patent on January 28 for Tangem’s technology pertaining to the backup of private keys.
The patent, which is called “Systems and Methods for Transferring Secret Data via an Untrusted Intermediary Device,” describes a way to use self-custodial wallets to help users keep track of their private keys or seed phrases.
The technology is designed to improve both the security and functionality of self-custodial wallets by facilitating secure transmissions of private keys between their hardware and devices, such as smartphones.
Tangem State reasons for transferring private keys
Self-custody, by definition, pertains to the autonomous storage of cryptocurrency assets without reliance on any third party. Users achieve this by receiving a private key or a sequence of characters that serves as a password to access their assets.
Although self-custody grants users complete control over their assets, it is susceptible to risks such as the theft or loss of private keys, which presents a considerable obstacle to widespread adoption.
Tangem’s private key backup technology allows users to benefit from self-custody without the need for direct private key management. Instead, it facilitates this process through the creation of backup authentication devices.
The main features of Tangem’s patented technology are a backup process that doesn’t use seeds, full end-to-end encryption, transmission without a trusted middleman, and authentication that can’t be changed.
Elliptic Curve Diffie-Hellman (ECDH) and other cryptographic methods are used in the technology to make it safe to exchange private keys and run key derivation functions.
Tangem’s backup technology employs a mechanism for transmitting the private key as confidential information between two trusted devices—such as a Tangem card or a ring—through an untrusted intermediary, such as a smartphone.
As articulated by Andrey Lazutkin, the Chief Technology Officer of Tangem, the term “untrusted intermediary” signifies that the technology does not necessitate reliance on user devices, such as smartphones.
The concept entails that the card transmits the key to another card, and it is entirely irrelevant which device is facilitating this transfer—be it a phone, regardless of its model, firmware, or whether it is rooted, infected with viruses, or otherwise.
Additionally, he said that the idea of private key backups might make the self-custody process easier, but that people in the community are skeptical about similar advances that have happened in the past.
Ledger, a prominent provider of hardware self-custodial wallets, encountered significant opposition from the community regarding its cloud-based private key recovery system, which was introduced in 2023.
The French hardware wallet provider still pushed out the tech in late 2023. In late 2024, Tangem faced significant criticism for inadvertently disclosing the private keys of certain users through email communications, a consequence of a critical security vulnerability within its mobile application.
Tangem subsequently recognized the issue, stating that the incident was attributable to a defect in the mobile application’s log processing, which has since been “completely rectified.”
In accordance with a widely recognized community adage, “Not your keys, not your coins,” numerous Bitcoin enthusiasts express opposition to entrusting a private key to any party other than the rightful proprietor.
Rather than depending on key encryption and transfer, some individuals opt to store their seed phrases using physical backup solutions, such as fireproof metal plates, or more advanced methods like Shamir Backup.
