Metaexplorer is an independent educational publisher. BEKTAS DİJİTAL İÇERİK STÜDYOSU ANONİM ŞİRKETİ has no connection, affiliation, endorsement, sponsorship, partnership or agency relationship with MetaMask or Consensys. MetaMask is a trademark of its owner. It is named here only to identify the software being described. Metaexplorer provides no support service, no recovery service and no software.
What this article covers
- What this article explains
- How key material is held in a self-custodial wallet, what a Secret Recovery Phrase is, what a token approval authorises and which observable patterns precede a loss of access.
- What it does not cover
- This article does not explain how to obtain, install, fund or use the software, and it gives no investment, financial, tax or legal advice.
- Who wrote it
- Leyla Bektas, writing for Metaexplorer.
- Last reviewed
- A standing note
- No page on this website will ever ask for a Secret Recovery Phrase, a private key or a password, and the website contains no forms of any kind.
Wallet security, for a beginner, means keeping control of the secret material that authorises transactions on a blockchain network. MetaMask is a self-custodial wallet application, named in Japanese as メタマスク, that holds that material on the user's own device. Security therefore rests on two things: the protection of the device, and the decisions a person makes when a confirmation screen appears.
This article describes general security practices for a person who already uses the software, and it explains mechanisms rather than steps.
What is a self-custodial wallet?
A self-custodial wallet is software that keeps the keys to a blockchain account on the user's own device rather than on a company server. The Secret Recovery Phrase is the ordered list of words from which every key in that wallet is derived; other writing calls it a seed phrase, or シードフレーズ in Japanese. Control of that phrase is control of the accounts.
A custodial arrangement places equivalent keys with a custodian instead, which changes who is able to reinstate an account.
| Property | Custodial arrangement | Self-custodial arrangement |
|---|---|---|
| Who holds the keys | A custodian holds them for the account holder. | The account holder's own device holds them. |
| Reinstating an account | The custodian can reinstate it after its own identity checks. | The Secret Recovery Phrase is the only route. |
| Dependence on a provider | Access depends on the custodian remaining operational. | Access depends on no company at all. |
| Signing a transaction | The custodian signs after an account instruction. | The device signs after an explicit confirmation. |
| Main point of exposure | The custodian's systems and account credentials. | The device, the stored phrase and each confirmation. |
| Counterparty | A contractual relationship exists with the company. | No counterparty holds the keys. |
Key points
- Self-custody places the keys on a device the account holder controls.
- The Secret Recovery Phrase derives every key in the wallet.
- A balance is a record on the network, not a file inside the software.
What does メタマスク セキュリティ actually protect?
The software protects key material held on one device. It encrypts that material while the wallet is locked, and it requests an explicit confirmation before anything is signed. It cannot protect a phrase that a person has typed elsewhere, because a signature made with the correct keys is indistinguishable from any other.
A loss in self-custody follows a disclosure, an approval or a lost copy of the phrase, rather than a defeat of the cryptography. The subject therefore has two parts. One part is defended by the software, and the other by the decisions of the person using it.
Key points
- Encryption and the local password defend key material on the device.
- The confirmation screen defends against an unintended instruction, once it is read.
- No part of the software can reverse a correctly signed transaction.
How does a Secret Recovery Phrase work?
A Secret Recovery Phrase encodes one large secret number as a sequence of ordinary words taken from a fixed public word list. BIP-39, the Bitcoin Improvement Proposal for mnemonic codes, defines that word list and the conversion of the phrase into a seed. BIP-32 defines how a master key derived from that seed produces child keys in a defined order.
Deterministic derivation is the property by which one phrase always produces the same keys in the same sequence. That property is the reason a phrase can reconstruct a wallet on another device. It is equally the reason a disclosed phrase reconstructs the same wallet for another person.
Key points
- The phrase is a readable encoding of a single secret number.
- Derivation follows the published standards BIP-39 and BIP-32 rather than any one company.
- The checksum defined in BIP-39 detects a copying mistake, not a disclosure.
Why does nobody legitimate ever ask for a Secret Recovery Phrase?
A Secret Recovery Phrase is not required for support, verification, migration, a balance check or a compensation claim. No legitimate party has a technical reason to receive it, because the phrase grants complete and irreversible control of every account derived from it. A request for the phrase is therefore a signal in itself.
The MetaMask Terms of Use, published by Consensys Software Inc., state that the publisher does not receive or store a wallet password, a private key or a Secret Recovery Phrase.
Never disclose a Secret Recovery Phrase, and never enter it into any website.
The same reasoning covers a private key and the local wallet password. Phishing is the practice of imitating a familiar interface so that a person supplies a secret voluntarily.
Key points
- Possession of the phrase is possession of the accounts.
- The published terms of the software state that its publisher does not receive or store the phrase.
- The request itself is the signal, whatever the page or message resembles.
What is a token approval?
A token approval is a permission recorded on the blockchain that allows a smart contract to move a stated quantity of one token out of an account. EIP-20, the Ethereum token standard, defines that permission and the allowance it records. An approval is separate from a transfer: it is signed once, and it remains in force until a later transaction changes it.
An unlimited allowance is an approval with no practical upper bound, so the contract may move any quantity of that token at any later time. A review screen is presented before an approval is signed, and it names the contract, the token and the quantity being authorised.
Key points
- An approval grants permission to move tokens; it is not itself a transfer.
- An unlimited allowance has no quantity ceiling and no expiry.
- Approvals persist after the transaction that first used them.
How do people lose access?
This section describes four patterns, and each one is observable from the account holder's side. The first is disclosure of the Secret Recovery Phrase to another party. The second is approval of a transaction whose effect the signer did not understand. The third is entry of the phrase into a page that imitates a familiar interface.
The fourth is loss of the only copy of the phrase, through hardware failure, damage or misplacement. In that pattern no other party is involved, and no procedure exists that reproduces the phrase.
Key points
- These patterns involve a disclosure, an approval or a lost copy.
- A transaction confirmed by the account holder is final on the network.
- An imitation page is recognised by its request rather than its appearance.
What is a hardware wallet, as a category?
A hardware wallet is a category of dedicated device that keeps key material inside its own chip and signs transactions there. The transaction details appear on the device screen, and a physical action on the device completes the signature. The design separates the approval step from the general-purpose computer that is connected to the internet.
This website discusses no manufacturer, model or purchase route. A device of this kind still depends on a Secret Recovery Phrase held by its owner, and it cannot judge whether an approval is reasonable.
Key points
- Key material stays inside the device and is used there.
- The device screen is a second, independent view of the transaction.
- A Secret Recovery Phrase still exists and still requires safe handling.
How can a beginner check what they are approving?
A confirmation screen is the last point at which a transaction can be refused. The fields it presents include the receiving address, the network in use, the value being sent and the estimated network fee. For a contract interaction it also names the function being called and the permission being granted.
An interface may add a simulated result, which states the expected change to the account balance. Each field describes a consequence that becomes final once the transaction is signed.
Key points
- Address, network, value and fee describe an ordinary transfer.
- Contract, function and quantity describe an approval.
- The quantity field separates a single-use permission from a standing one.
What does this article deliberately not tell you?
Self-custody moves responsibility to the account holder, and that responsibility includes the possibility of an irreversible mistake. Software also changes, so every security statement here can be checked against the documentation published for the software actually in use.
That documentation is the authority for its own product, and this article is not. There is no support channel, no recovery procedure and no reader account associated with this website.
Editorial correspondence about the content of these articles may be sent to contact@metaexplorer.org. That address is not a support, recovery or account service, and no enquiry about a wallet is answered there.
Key points
- General precautions reduce exposure; they do not eliminate it.
- The documentation of the software in use overrides any general description.
- No message about a wallet ever originates from this website.
Glossary
- Allowance
- The quantity of one token that an approved contract may move from an account; in Japanese, アローワンス.
- Blockchain
- A shared digital record that many independent computers store and verify at the same time; in Japanese, ブロックチェーン.
- Hardware wallet
- A dedicated device that holds key material and signs transactions internally; in Japanese, ハードウェアウォレット.
- Private key
- A secret value that authorises transactions from one blockchain address; in Japanese, プライベートキー.
- Secret Recovery Phrase
- The ordered list of words from which every key in a wallet is derived; in Japanese, シードフレーズ.
- Self-custody
- The arrangement in which the account holder alone holds the private keys, rather than a company holding them; in Japanese, セルフカストディ.
- Wallet
- Software or a device that stores private keys and creates signatures; in Japanese, ウォレット.
Frequently asked questions
Does any legitimate party ever ask for a Secret Recovery Phrase?
No party with a legitimate purpose asks for it, because the phrase grants complete and irreversible control of every account derived from it. The MetaMask Terms of Use state that the publisher does not receive or store a Secret Recovery Phrase. Never disclose a Secret Recovery Phrase, and never enter it into any website.
Are tokens stored inside the wallet software?
Balances are entries in the blockchain record, and the software holds only the keys that authorise changes to those entries. Removing the software from a device does not move a balance.
Where is the underlying technology explained?
A separate article on this website, What Is Blockchain and How Does It Work?, describes how a blockchain records transactions and why recorded entries are difficult to alter. It was published on .
Does the local password protect the same thing as the Secret Recovery Phrase?
No. The password unlocks encrypted key material on one device and applies only to that installation. The Secret Recovery Phrase reconstructs the same accounts in any software that follows the same standards.
Does a token approval expire without further action?
An approval remains in force until a later transaction changes it, so an unlimited allowance persists indefinitely. A time limit exists only where the contract defines one.
Sources
- Consensys Software Inc., "MetaMask Terms of Use" — the publisher's statement about the key material it does not receive or store.
- Bitcoin Improvement Proposals repository, "BIP-39: Mnemonic Code for Generating Deterministic Keys" — the word list, the checksum and the conversion of a phrase into a seed.
- Bitcoin Improvement Proposals repository, "BIP-32: Hierarchical Deterministic Wallets" — the derivation of child keys from a master key.
- Ethereum Improvement Proposals, "EIP-20: Token Standard" — the approval and allowance mechanism described here.
About this article
This article provides general educational information about how wallet software handles key material. It is not investment, financial, legal or tax advice.
Metaexplorer sells nothing to readers. It provides no wallet, exchange, custody, recovery or support service, and it will never request a Secret Recovery Phrase, a private key or a password.
No security practice removes all risk. These points are general precautions rather than a guarantee.