It’s great to see hip-to-chain technology.
Does anyone know how Tangem wallets manage the public key from the private key? Is it possible to program on importing an old key/seed or generating a new private key?
Why are there dedicated MICROCHIPS for each cryptocurrency?
I don't think they have any encryption of the service but the wallet design looks strange, I thought they might modify the design to carry the public key but you can modify the final design yourself.
those are segments taken from the Tangem FAQ & hopefully answers your questions:
A wallet private key, which is the key to the ownership of blockchain assets, is always securely generated inside the Tangem chip. The key cannot be injected from outside, backed up or restored. Thus, the card holds a unique and unclonable instance of the wallet.At the moment, Tangem supports the following cryptocurrencies: BTC, ETH, XRP, BCH, XLM, ADA.
In order to optimize for user experience, we kept it simple. Each Tangem Card is fixed to a certain cryptocurrency and can hold one private key at a time.Each Tangem Card holds a secure chip that allows you to store and carry digital assets. The private key is generated by and permanently stored within the chip. Nobody has access to it either during or after the manufacturing process. This means that nobody can input, export or make a copy of this key.The security of Tangem technology is audited by the Kudelski Group, a listed Swiss security company. The report is available here. After the audit, the chip firmware cannot be modified even by Tangem. Its intactness in each Card can be verified with the Tangem App. The app and the NFC communication protocol are open source.Copyright disclaimer: The above are not my words, the text is taken (as is) from the Tangem Faq.
Source:
https://shop.tangem.com/pages/tangem-faqsNot quite sure how "how Tangem wallets manage the public key from the private key". I know that you can re-initiate the card (i.e. create a new private/public key pair). However, I am not quite sure if for every transaction a new public key is being created (if this is your question)
Further, if you would like to program Tangem cards, and use the same card for multiple blockchains/cryptocurrencies (one at a time), there is a development kit. You can either use their GitHub code to create your own application or use their android development kit app (from the play store), to program a card with the characteristics of your preference.
Here is a summary of what you can do:
choose blockchain and signature algorithm, coin or token, define lifecycle, set up protection and protocol encryption, play with 2FA and issuer secure channel, check card and firmware attestation, load and read up to 100kb of extra data.Source: above text taken from "Tangem Development Kit" description
https://shop.tangem.com/products/tangem-developer-kit