EviSeed NFC HSM
Seed phrases, keys, offline and online transaction signing
EviSeed Technology
Keep the seed on the NFC HSM. Sign offline (air-gap) or online (Auto) – without exporting the key.
What is EviSeed NFC HSM and how does it work?
EviSeed is Freemindtronic-s patented technology for blockchain services on NFC HSM devices: encrypted BIP39 seed phrases, derived keys, and air-gap signing. It is not a cloud wallet and it does not require an online account. The seed stays in the contactless module; the phone is a terminal, not a custodian.
A seed phrase (BIP39, typically 12 to 24 words) is the recovery secret of a crypto wallet. If it is lost, funds are lost. If it is copied in clear text, funds can be stolen. EviSeed generates, imports or scans BIP39 phrases with checksum control, then stores them encrypted with your own keys, including segmented key authentication (Freemindtronic patent).
You can keep the ciphertext on Freemindtronic NFC HSM devices (SeedNFC, DataShielder, DataShielder Defense) and on other media via an AES-256 or RSA-4096 encrypted QR, OpenPGP, NFC Beam, or proximity transfer. Compatible BIP39 word lists include English, French, Spanish, Italian, Japanese, Korean, Simplified Chinese and Traditional Chinese.
On SeedNFC and DataShielder Defense, the same NFC HSM identifies a public address and signs without sending the mnemonic or the private key off the device. The Freemindtronic app signer covers EVM (send crypto), XRPL Payment, Stellar (XLM) Payment, Cardano (ADA) Payment and Solana transfer, plus SeedNFC test and network-context QR. Each chain can be used offline (air-gap export) or online (Auto: public RPC / network data, then optional broadcast of the already-signed transaction).
EviSeed is built against paper, metal plates and files that leave the seed in the clear. The NFC HSM has no battery, no cloud and no persistent link to a third-party server.
- Simple – generate or import BIP39 with checksum; no engraving, no retyping twelve or twenty-four words by hand.
- Air-gap by design – the private material never leaves the NFC HSM. Offline mode exports the signed payload; online Auto broadcasts only that already-signed raw transaction.
- Durable – ISO 15693 energy harvesting, expected data retention of decades, no recharge cycle.
- Secure – AES-256 / RSA-4096 / OpenPGP, segmented keys, PIN or biometrics on the phone app, screenshot protection on signer screens.
- Versatile – NFC HSM, encrypted QR, EviKey / EviDisk, web extension. Restore into any BIP39 wallet, or sign from the HSM.
- Product-aware – SeedNFC is the dedicated cold-wallet product. DataShielder NFC HSM does not require blockchain. DataShielder Defense may use EviSeed services optionally. Collectible / NFT identity is not stored as chain metadata inside the NFC Label payload.
NFC HSM blockchain datasheet
One secure tap, multiple blockchain workflows
EviSeed keeps the recovery phrase and signing keys inside the NFC HSM. Use the Android app to prepare, review and sign a transaction without turning the phone into the key holder. Each supported chain has its own isolated engine, with a clear choice between offline air-gap export and online Auto delivery.
Shared delivery layer: payment URI and QR input, FMT-NC network context, human-readable receipt, transaction hash or signature, and explorer verification QR. No seed or private key is placed in those outputs.
Bitcoin
BTC – BIP39
Generate, import and protect a checksummed recovery phrase for compatible Bitcoin wallets.
Encrypted backup – Wallet restore
Ethereum + EVM
ETH – ERC-20
Sign native and token transfers on Ethereum or another EVM network using its chain ID.
Offline – Auto – EIP-1559
XRP Ledger
XRP – PAYMENT
Prepare and sign XRP payments with destination tag support on Testnet or Mainnet.
Offline – Auto – Explorer receipt
Stellar
XLM – PAYMENT
Sign native XLM payments with memo and time bounds for controlled transaction delivery.
Offline – Auto – Memo
Cardano
ADA – CIP-1852
Review UTXO context and sign native ADA payments while the private key stays in the HSM.
Offline – Auto – UTXO
Solana
SOL – SYSTEM TRANSFER
Sign native SOL transfers with a recent blockhash for offline export or online sending.
Offline – Auto – Devnet / Mainnet
Identify, then sign
Tap #1 derives only the public address (BIP39 or CRYPTO label) and wipes secrets from RAM before any network call. Tap #2 signs the sealed transaction. The same wallet must be used for both taps.
Air-gap or Auto
Offline (air-gap): NFC sign on the HSM, then export raw / QR / clipboard – nothing is sent to a node. Online (Auto): the app fetches public network data (nonce, fees, blockhash, sequence, UTXO context) over HTTPS, you review, you tap the HSM, then you may broadcast the unchanged signed payload. Both modes keep the private key inside the NFC HSM.
Receipt, not a seed dump
After sign/send you get a human blockchain receipt (network, amount, short addresses, tx hash or Solana signature, explorer URL). The document is built so it cannot contain a mnemonic or private key. Verification QR carries the explorer URL or the hash only.
| Capability on NFC HSM | Status | What it actually does |
|---|---|---|
| BIP39 generate / import / encrypted backup | Available | Checksummed phrase, segmented keys, encrypted QR (AES-256 / RSA-4096), NFC clone |
| Bitcoin + Ethereum wallet labels | Available | HD derivation on the HSM; restore into any BIP39 wallet |
| Offline NFC sign (air-gap) | Available | EVM, XRPL, Stellar, Cardano, Solana: review, tap HSM, export raw / QR / clipboard – no node |
| Online sign + send (Auto) | Available | Public HTTPS for network data, then optional broadcast of the unchanged signed payload; network-context QR (FMT-NC) for all chains |
| EVM native transfer (EIP-155 / EIP-1559) | Available | ETH and EVM chains; Auto presets Ethereum Mainnet and Sepolia; other chain IDs in Advanced |
| ERC-20 transfer | Available | Selector transfer(address,uint256); trusted display: USDC Ethereum + USDC Sepolia |
| XRPL native Payment | Available | XRP drops, destination tag; Testnet and Mainnet; offline export or live submit |
| Stellar native Payment | Available | XLM Payment (memo, time bounds); NFC sign offline or with online network context |
| Cardano native Payment | Available | ADA CIP-1852; UTXO payment; NFC sign offline or with online network context |
| Solana SystemProgram transfer | Available | BIP39 to SLIP-0010 m/44’/501’/0’/0′; offline export or online send (Devnet / Mainnet policy) |
| Payment QR / paste | Available | 0x and EIP-681, xrpl:/ripple:, solana:, plus FMT-NC network-context QR |
| SeedNFC test path | Available | Dedicated SeedNFC entry in the signer shell |
EVM Auto public RPC presets: Ethereum Mainnet (1) and Sepolia (11155111). Other EVM networks (BNB Smart Chain, Polygon, Arbitrum, Optimism, Base, Avalanche C-Chain, Gnosis, Fantom, Ethereum Classic, -) use the same EVM engine in Advanced / air-gap with the chain ID you supply.
No cloud account. The Freemindtronic NFC HSM Android app (v3.2.2 and later) talks to the card over ISO 15693.
- Get a compatible NFC HSM – SeedNFC for the dedicated cold wallet, or DataShielder Defense if you already use that HSM.
- Install the Freemindtronic NFC HSM Android app (Android 6+). Unlock with your device PIN / biometrics – that is local, not a Freemindtronic login.
- Tap the HSM. Generate a BIP39 phrase (12-24 words) or import one. The checksum must pass.
- Optional: clone with an RSA-4096 encrypted QR, NFC Beam, or EviKey / EviDisk.
- Store the physical HSM offline. To restore a software wallet, export/decrypt only on a trusted phone. To move coins without exporting the seed, open Sign a transaction: send crypto (EVM), XRP, XLM, ADA or SOL. Choose offline (export signed payload) or online Auto (network data + optional broadcast).
Payment QR on the signer: raw 0x / EIP-681, xrpl: / ripple:, solana:. Scan network-context QR (FMT-NC) for fees, nonce, blockhash, sequence or UTXOs. Secrets never go in that QR.
EviSeed is a technology layer, not a single Label. Products consume it differently.
Android NFC HSM (Freemindtronic App)
The contactless system stores encrypted seeds and keys in NFC EEPROM. In Sign a transaction you get: send crypto (EVM), SeedNFC test, XRP payment, XLM payment, ADA payment, SOL transfer, and network-context QR. Offline air-gap export and online Auto (public network data + optional broadcast) are both available. Compatible technologies in the same app include EviCore, EviVault, EviPass, EviSeed and Defense.
Web extension (Chromium and Firefox)
PassCypher / DataShielder HSM PGP extensions generate or save OpenPGP ciphertext with segmented keys (patent). Any file or removable media can hold the backup. The extension is compatible with the Android HSM for automatic filling of the three segmented-key fields.
Hardware around the HSM
EviKey / EviDisk NFC, BLE keyboard emulator, and printed encrypted QR remain valid backup media. They do not replace the HSM for air-gap signing: signing requires a SeedNFC or Defense-class module and the Android app.
How to choose the best solution to protect your recovery phrase
Compare where the secret actually lives, and whether you can sign without printing it in the clear.
| Solution | Advantages | Limits |
|---|---|---|
| Paper | Cheap, offline | Fragile, visible in clear, not encryptable, not cloneable safely |
| Metal | Fire / water / shock | Expensive, still in clear, not segmentable |
| Disk / password manager | Compact, can encrypt | Malware, backups, often online |
| Shamir / SSS software | Split shares | Complex operational load, host still sees the phrase when reconstructed |
| EviKey / EviDisk | Encrypted removable NFC media | Needs an NFC reader; not the signer |
| EviSeed NFC HSM | Encrypted BIP39, segmented keys, no battery, offline and online NFC sign (EVM, XRP, XLM, ADA, SOL), encrypted QR clone | Requires the Android NFC HSM app and a compatible module |
Compatibility of EviSeed with wallets and blockchains
Two different questions: (1) can I backup a BIP39 phrase used by a wallet, and (2) can the NFC HSM sign that chain without exporting the seed.
A cold / hardware / hot wallet that speaks BIP39 can be backed up with EviSeed. The NFC HSM signs EVM, XRPL, Stellar, Cardano and Solana without exporting the seed (offline or online).
BIP39 backup and HSM signing
- Bitcoin, Bitcoin Cash, Litecoin, Dogecoin – BIP39 HD backup / restore
- Ethereum, Ethereum Classic, BNB Smart Chain, Polygon, Arbitrum, Optimism, Base, Avalanche C-Chain, Gnosis, Fantom and other EVM chains – BIP39 + NFC HSM EVM signer (offline and online)
- XRPL (XRP) – NFC HSM Payment, offline and online
- Stellar (XLM) – NFC HSM Payment, offline and online
- Cardano (ADA, CIP-1852) – NFC HSM Payment, offline and online
- Solana (SOL, BIP39 SLIP-0010) – NFC HSM transfer, offline and online
- Hardware and software wallets that expose BIP39: Ledger, Trezor, KeepKey, Exodus, Trust Wallet, MetaMask, Electrum, Atomic Wallet
Backup vs on-HSM signing (all paths below are operational):
| Wallet / chain | BIP39 backup | NFC HSM sign | Notes |
|---|---|---|---|
| Bitcoin | Yes | Wallet label / restore | Legacy HD UI path on the HSM; restore into any BIP39 BTC wallet |
| Ethereum | Yes | Yes – offline and online | Native ETH + ERC-20; Auto RPC presets chain 1 and Sepolia; other EVM chain IDs in Advanced |
| BNB Smart Chain / other EVM | Yes | Yes – offline and online | Same EVM engine; Auto public RPC presets are ETH/Sepolia; other EVM nets via Advanced chain ID |
| XRPL (XRP) | Yes (FMT mapping) | Yes – offline and online | Native XRP Payment; Testnet and Mainnet; not a third-party hosted Ripple backup |
| Solana | Yes (BIP39 SLIP-0010) | Yes – offline and online | SystemProgram transfer; BIP44 coin 501; Devnet / Mainnet policy on live send |
| Cardano | Yes (CIP-1852) | Yes – offline and online | Native ADA Payment from NFC HSM (UTXO + TTL) |
| Stellar (XLM) | Yes (FMT mapping) | Yes – offline and online | Native XLM Payment (memo, time bounds) |
| Polygon / Arbitrum / Optimism / Base / Avalanche | Yes | Yes – offline and online | Same EVM signer; set chain ID in Advanced (or Auto when endpoint is configured) |
| Litecoin / Bitcoin Cash / Dogecoin | Yes | BIP39 restore | Backup on HSM; restore into the chain wallet |
| Polkadot / Substrate | No (native sr25519) | No | Different mnemonic scheme – do not import a Substrate phrase as BIP39 |
| Ledger / Trezor / KeepKey | Yes | Restore or HSM sign* | They generate BIP39; you can backup that phrase on EviSeed |
| MetaMask / Trust / Exodus | Yes | Restore or HSM sign* | Enable / export BIP39 seed in those products own settings |
* HSM sign = EVM, XRP, XLM, ADA and SOL from the Sign a transaction menu (offline or online). Never type a seed into a website to check compatibility.
Substrate / Polkadot mnemonics are not BIP39: do not import them as a Bitcoin-style phrase. Other BIP39 wallets (Ledger, Trezor, MetaMask, Trust, Exodus, Electrum, Atomic) backup on EviSeed and can be signed on-HSM when the chain is EVM/XRP/XLM/ADA/SOL.
EviSeed compatibility universe
Cryptocurrencies, EVM networks, token paths and connected technologies currently covered by BIP39 backup, NFC HSM signing or the EviSeed delivery layer.
Cryptocurrencies and blockchain networks
BitcoinBIP39 backup / restore
Bitcoin CashBIP39 backup / restore
LitecoinBIP39 backup / restore
DogecoinBIP39 backup / restore
EthereumNative + ERC-20 signing
Ethereum ClassicEVM chain ID
BNB Smart ChainEVM chain ID
PolygonEVM chain ID
ArbitrumEVM chain ID
OptimismEVM chain ID
BaseEVM chain ID
Avalanche C-ChainEVM chain ID
GnosisEVM chain ID
FantomEVM chain ID
XRP LedgerOffline / online Payment
StellarXLM Payment
CardanoADA CIP-1852 Payment
SolanaSOL System transferSmart contracts, tokens and on-chain identity
ERC-20 transferSelector a9059cbb
USDCTrusted display on Ethereum / Sepolia
EVM native assetsEIP-155 / EIP-1559
On-chain identityEVM contract + token IDXRPL identityNFTokenID reference
Solana identityMint-address referenceScope note: ERC-20 transfer is the implemented smart-contract call. On-chain identity entries describe references already minted elsewhere; they do not claim NFT minting, generic contract deployment, ERC-721/1155 execution or SPL-token signing.
NFC HSM, IoT and delivery interfaces
SeedNFCDedicated cold-wallet HSM
DataShielder DefenseOptional EviSeed servicesISO 15693 NFCBattery-free energy harvesting
Android 8+Freemindtronic NFC HSM app
FMT-NC QRNetwork context without secrets
EviKey / EviDiskEncrypted clone media
OpenPGPEncrypted backup workflow
BLE keyboardProximity transfer interfaceHuman receiptHash, signature and explorer QR
Air-gap exportRaw, Base64, QR or clipboard
Online AutoPublic context + optional broadcastPayment URIEIP-681, xrpl: and solana:
EviSeed partner for seed security and HSM signing
Freemindtronic (Andorra) designs the NFC HSM, the patents, and the Android app. EviSeed is the blockchain/seed layer inside that stack.
1. Encryption and segmented keys
Your phrase is encrypted with keys you control. Segmented key authentication (patent) splits those keys so a single leak is not enough. RSA-4096 QR clones and AES-256 / OpenPGP exports stay in that model.
2. Backup without a cloud account
Scan or generate BIP39, write the HSM, optional encrypted QR. No Freemindtronic login, no seed upload.
3. Durable NFC HSM
No battery, energy harvesting (ISO 15693), industrial EEPROM retention. Designed to outlast phones and paper.
4. BIP39 + published HSM signers
Backup any BIP39 wallet. Sign from SeedNFC / Defense without exporting the seed: EVM, XRPL, Stellar, Cardano and Solana, offline or online.
5. Ecosystem
Android NFC HSM app, Chromium/Firefox OpenPGP extension, EviKey / EviDisk, EviPass for authentication – same company, same key-hygiene rules.
6. Established vendor
Freemindtronic ships NFC HSM products (PassCypher, DataShielder, SeedNFC) and licenses the patents to manufacturers who need the same model.
Patent license for EviSeed technology
Freemindtronic licenses EviSeed to companies that want NFC HSM seed backup and/or air-gap signing inside their own product. The license is a ready cryptographic and product model, not a white-label cloud.
1. Access to the patented model
Segmented keys, NFC HSM storage, encrypted QR clone, BIP39 checksum flow – unique to the Freemindtronic patents.
2. Trust
Same stack used in SeedNFC, DataShielder and PassCypher NFC HSM products.
3. Time
You do not re-implement air-gap BIP39 + HSM signing from scratch.
4. Technical support
Integration support from Freemindtronic during bring-up.
5. Scope
Licensees can take seed backup only, or the full NFC HSM signing set (EVM, XRP, XLM, ADA, SOL; offline and online), depending on the agreement.
Ask for terms via the contact page.
What sets EviSeed apart
The difference is architectural: secrets remain in a passive NFC HSM while the phone handles the user experience. The same protected foundation covers backup, restoration and multi-chain signing, with offline air-gap and online Auto paths that stay understandable from review to receipt.
Security that remains usable
Checksummed BIP39, segmented keys and encrypted recovery options support daily use without requiring the seed to become a permanent hot-wallet secret.
Interoperability without lock-in
Standard BIP39 recovery supports compatible wallets, while on-device signing covers EVM, XRP, XLM, ADA and SOL. The user keeps a portable recovery path instead of depending on a proprietary account.
One hardware trust anchor
The Android NFC HSM app, encrypted clones, OpenPGP tools and optional authentication services can share a hardware-rooted security model without placing blockchain secrets in the cloud.
Designed to scale beyond one product
The patented model can be licensed by manufacturers that want hardware-backed customer custody without building seed storage into an application backend.
Clear separation of duties
Custody, transaction preparation, signing and access control remain distinct. Each layer does its job without exposing the mnemonic to the network-facing workflow.
Multilingual application
International
The Freemindtronic NFC HSM app follows the phone language. Translations include Arabic, Catalan, Chinese, English, French, German, Hindi, Italian, Japanese, Portuguese, Romanian, Russian, Spanish, Ukrainian (UK English added in recent 3.2.x builds).
BIP39 word lists on SeedNFC: English, French, Spanish, Italian, Japanese, Korean, Simplified Chinese, Traditional Chinese.
PEACE OF MIND
Install locally. No account. Your language on the phone.
MORE LANGUAGES
Extra locales can be added on request.
EviSeed eco-friendly technology
Freemindtronic designs the HSM so that secrecy does not depend on a data centre.
NO CLOUD
Air-gap storage in the HSM EEPROM. No seed on Freemindtronic servers. Skipping the cloud also skips that water and electricity footprint.
Lifetime
Designed for decades of data retention without a power source.
NFC energy harvesting
ISO 15693. The phone field powers the chip for the tap. No cell inside the card.
No battery
Nothing to recharge. The HSM works when you tap it.
Recyclable
Electronics follow RoHS. Coating and ABS shell are recyclable.
Second-hand market
Factory format is possible so a device can be reset and reused without leftover secrets.
Glossary
Terms used on this page. Expand a row for the definition.
BIP39seed
Checksummed mnemonic (12 to 24 words) used as a crypto wallet backup. EviSeed generates, imports and encrypts BIP39 phrases. Word lists include EN, FR, ES, IT, JA, KO, ZH and ZH-TW.
NFC HSMhardware
Contactless hardware security module (ISO 15693). It stores encrypted secrets in EEPROM, harvests energy from the phone field, has no battery, and signs without exporting the private key.
Offline / air-gap signingmode
You review, tap the HSM, then export the signed payload (raw hex, Base64, QR or clipboard). Nothing is sent to a blockchain node.
Online / Auto signingmode
The app fetches public network data (nonce, fees, blockhash, sequence, UTXOs) over HTTPS or from an FMT-NC QR. After NFC sign you may broadcast the unchanged signed transaction.
Segmented key authenticationpatent
Freemindtronic patent: encryption keys are split into segments. All required segments must be reunited to decrypt. Used with AES-256, RSA-4096 QR clones and OpenPGP.
FMT-NCQR
Versioned network-context QR (FMT-NC/1). It carries fees, nonce, chain and expiry for SIMPLE autofill. It never encodes a seed, mnemonic or private key. In the app: Scan network-context QR.
SeedNFCproduct
Freemindtronic cold-wallet NFC HSM dedicated to EviSeed. DataShielder does not require blockchain; DataShielder Defense may use EviSeed optionally.
Blockchain receiptproof
Human document after sign or send: network, amount, short addresses, tx hash or Solana signature, explorer URL. Built so a mnemonic or private key cannot appear. Verification QR is the explorer URL or the hash only.
EIP-681 / xrpl: / solana:payment URI
Standard payment QR or paste formats. EVM: raw 0x or ethereum: URI. XRPL: xrpl: or ripple:. Solana: solana: URI or base58 address. Secrets and raw signed blobs are rejected.
Note: this page is informational. It is not investment advice. EviSeed does not custody your funds. Independently verify transactions on a public explorer. Research and, if needed, consult professionals before any crypto decision.