Wallet Logo

Melis Bitcoin, Bitcoin Cash, L

Google Play App Store Website
Developer
Melis (Android)
Melis s.r.l. (iPhone)
Released
Android: 30th January 2017
iPhone: 7th June 2017
Source code
Public on github
Custody
Self-custodial: The user holds the keys
Status
No longer available for download.

Passed all 7 tests

We check each wallet from its code to the app on your device, asking these questions in order:

Is this product the original?

The answer is "yes".
If the answer were "no", we would mark it as "Fake" and the following would apply:

The answer is "no". We marked it as "Fake".

We did not ask this question because we failed at a previous question.
If the answer were "no", we would mark it as "Fake" and the following would apply:

The bigger wallets often get imitated by scammers that abuse the reputation of the product by imitating its name, logo or both.

Imitating a competitor is a huge red flag and we urge you to not put any money into this product!

The product cannot be independently verified. If the provider puts your funds at risk on purpose or by accident, you will probably not know about the issue before people start losing money. If the provider is more criminally inclined he might have collected all the backups of all the wallets, ready to be emptied at the press of a button. The product might have a formidable track record but out of distress or change in management turns out to be evil from some point on, with nobody outside ever knowing before it is too late.
Is it a wallet?

The answer is "yes".
If the answer were "no", we would mark it as "Not a wallet" and the following would apply:

The answer is "no". We marked it as "Not a wallet".

We did not ask this question because we failed at a previous question.
If the answer were "no", we would mark it as "Not a wallet" and the following would apply:

If it’s called “wallet” but is actually only a portfolio tracker, we don’t look any deeper, assuming it is not meant to control funds. What has no funds, can’t lose your coins. It might still leak your financial history!

If you can buy Bitcoins with this app but only into another wallet, it’s not a wallet itself.

The same goes for off-ramps that hold no balance at all: bitcoin (or gift cards) go in and fiat goes straight out to your bank. An off-ramp that keeps your fiat until you cash out is a wallet, just not for Bitcoin. One that keeps a bitcoin balance you can’t send out is ‘Can’t send or receive bitcoins’.

Is it for bitcoins?

The answer is "yes".
If the answer were "no", we would mark it as "A wallet but not for Bitcoin" and the following would apply:

The answer is "no". We marked it as "A wallet but not for Bitcoin".

We did not ask this question because we failed at a previous question.
If the answer were "no", we would mark it as "A wallet but not for Bitcoin" and the following would apply:

At this point we only look into wallets that at least also support BTC.

A product that can send and receive other coins but only tracks Bitcoin addresses read-only is a wallet, just not for Bitcoin, so it gets this verdict. ‘Not a wallet’ is for products that hold no coins at all, such as pure portfolio trackers.

The same goes for off-ramps that credit your bitcoin to a fiat balance you later cash out: the app holds your money, but not as bitcoin.

Can it send and receive bitcoins?

The answer is "yes".
If the answer were "no", we would mark it as "Can't send or receive bitcoins" and the following would apply:

The answer is "no". We marked it as "Can't send or receive bitcoins".

We did not ask this question because we failed at a previous question.
If the answer were "no", we would mark it as "Can't send or receive bitcoins" and the following would apply:

If it is for holding BTC but you can’t actually send or receive them with this product then it doesn’t function like a wallet for BTC but you might still be using it to hold your bitcoins with the intention to convert back to fiat when you “cash out”.

All products in this category are custodial and thus funds are at the mercy of the provider.

The product cannot be independently verified. If the provider puts your funds at risk on purpose or by accident, you will probably not know about the issue before people start losing money. If the provider is more criminally inclined he might have collected all the backups of all the wallets, ready to be emptied at the press of a button. The product might have a formidable track record but out of distress or change in management turns out to be evil from some point on, with nobody outside ever knowing before it is too late.
Does the product allow self-custody?

The answer is "yes".
If the answer were "no", we would mark it as "Custodial: The provider holds the keys" and the following would apply:

The answer is "no". We marked it as "Custodial: The provider holds the keys".

We did not ask this question because we failed at a previous question.
If the answer were "no", we would mark it as "Custodial: The provider holds the keys" and the following would apply:

A custodial service is a service where the funds are held by a third party like the provider. The custodial service can at any point steal all the funds of all the users at their discretion. Our investigations stop there.

Some services might claim their setup is super secure, that they don’t actually have access to the funds, or that the access is shared between multiple parties. For our evaluation of it being a wallet, these details are irrelevant. They might be a trustworthy Bitcoin bank and they might be a better fit for certain users than being your own bank but our investigation still stops there as we are only interested in wallets.

Products that claim to be non-custodial but feature custodial accounts without very clearly marking those as custodial are also considered “custodial” as a whole to avoid misguiding users that follow our assessment.

Balances on operator-dependent layers (Spark, Ark and similar) are judged by one question: “Can a user, with only what the app gives them and expecting help from nobody, actually force their money onto the Bitcoin blockchain?” Such a balance counts as self-custodial only for the part that the app itself shows the user could recover this way, calculated without network access at a fee rate the user chooses, and only once a recovery from that app has been demonstrated, because the app decides how the balance is split and therefore how much of it can come back. The rest of the balance is considered custodial.

We have to acknowledge that a huge majority of Bitcoiners are currently using custodial Bitcoin banks. If you do, please:

  • Do your own research if the provider is trust-worthy!
  • Check if you know at least enough about them so you can sue them when you have to!
  • Check if the provider is under a jurisdiction that will allow them to release your funds when you need them?
  • Check if the provider is taking security measures proportional to the amount of funds secured? If they have a million users and don’t use cold storage, that hot wallet is a million times more valuable for hackers to attack. A million times more effort will be taken by hackers to infiltrate their security systems.
The product cannot be independently verified. If the provider puts your funds at risk on purpose or by accident, you will probably not know about the issue before people start losing money. If the provider is more criminally inclined he might have collected all the backups of all the wallets, ready to be emptied at the press of a button. The product might have a formidable track record but out of distress or change in management turns out to be evil from some point on, with nobody outside ever knowing before it is too late.
Is the source code publicly available?

The answer is "yes".
If the answer were "no", we would mark it as "No source for current release found" and the following would apply:

The answer is "no". We marked it as "No source for current release found".

We did not ask this question because we failed at a previous question.
If the answer were "no", we would mark it as "No source for current release found" and the following would apply:

A wallet that claims to not give the provider the means to steal the users’ funds might actually be lying. In the spirit of “Don’t trust - verify!” you don’t want to take the provider at his word, but trust that people hunting for fame and bug bounties could actually find flaws and back-doors in the wallet so the provider doesn’t dare to put these in.

Back-doors and flaws are frequently found in closed source products but some remain hidden for years. And even in open source security software there might be catastrophic flaws undiscovered for years.

An evil wallet provider would certainly prefer not to publish the code, as hiding it makes audits orders of magnitude harder.

For your security, you thus want the code to be available for review.

If the wallet provider doesn’t share up to date code, our analysis stops there as the wallet could steal your funds at any time, and there is no protection except the provider’s word.

“Up to date” strictly means that any instance of the product being updated without the source code being updated counts as closed source. This puts the burden on the provider to always first release the source code before releasing the product’s update. This paragraph is a clarification to our rules following a little poll.

We are not concerned about the license as long as it allows us to perform our analysis. For a security audit, it is not necessary that the provider allows others to use their code for a competing wallet. You should still prefer actual open source licenses as a competing wallet won’t use the code without giving it careful scrutiny.

The product cannot be independently verified. If the provider puts your funds at risk on purpose or by accident, you will probably not know about the issue before people start losing money. If the provider is more criminally inclined he might have collected all the backups of all the wallets, ready to be emptied at the press of a button. The product might have a formidable track record but out of distress or change in management turns out to be evil from some point on, with nobody outside ever knowing before it is too late.
Is the decompiled binary legible?

The answer is "yes".
If the answer were "no", we would mark it as "Obfuscated" and the following would apply:

The answer is "no". We marked it as "Obfuscated".

We did not ask this question because we failed at a previous question.
If the answer were "no", we would mark it as "Obfuscated" and the following would apply:

When compiling source code to binary, usually a lot of meta information is retained. A variable storing a masterseed would usually still be called masterseed, so an auditor could inspect what happens to the masterseed. Does it get sent to some server? But obfuscation would rename it for example to _t12, making it harder to find what the product is doing with the masterseed.

In benign cases, code symbols are replaced by short strings to make the binary smaller but for the sake of transparency this should not be done for non-reproducible Bitcoin wallets. (Reproducible wallets could obfuscate the binary for size improvements as the reproducibility would assure the link between code and binary.)

Especially in the public source cases, obfuscation is a red flag. If the code is public, why obfuscate it?

As obfuscation is such a red flag when looking for transparency, we do also sometimes inspect the binaries of closed source apps.

As looking for code obfuscation is a more involved task, we do not inspect many apps but if we see other red flags, we might test this to then put the product into this red-flag category.

The product cannot be independently verified. If the provider puts your funds at risk on purpose or by accident, you will probably not know about the issue before people start losing money. If the provider is more criminally inclined he might have collected all the backups of all the wallets, ready to be emptied at the press of a button. The product might have a formidable track record but out of distress or change in management turns out to be evil from some point on, with nobody outside ever knowing before it is too late.

Distribution

Google Play Website

Build Verifications

Check your file

Drop the file you downloaded or installed to see if anybody verified it. Its SHA-256 is calculated in your browser.

or drop it here

Platform notes

On the Google Play Store, there are many apps that have Bitcoin in their name or description but don’t allow the user to use Bitcoin or they don’t look like Bitcoin wallets but turn out to be. We run our tests and document our findings.

Android

Free and Open Source (FOSS)

Free and Open Source (FOSS)

The wallet’s source code is published under a license approved by the Open Source Initiative (OSI) — such as MIT, GPL, Apache, or AGPL — allowing anyone to inspect, modify, and redistribute it. This is a prerequisite for independent security audits and reproducible builds. Licenses that are merely “source available” but not OSI-approved (e.g., those with Commons Clause restrictions, commercial use prohibitions, or other non-free terms) do NOT qualify. Reproducible builds are not sufficient alone.

  • Transparency: Anyone can verify what the code does — including whether it contains backdoors, bugs, or privacy-violating behavior.

  • Community auditing: More reviewers means vulnerabilities are more likely to be found and fixed.

  • Forkability: If the project is abandoned or goes rogue, the community can fork and continue it.

FOSS alone does not guarantee security. The released binary must also be reproducible from the public source to ensure users are actually running the code that was audited.

Why we list it for this wallet

MIT License

Source: README

Multi Signature

Multi Signature

Bitcoin allows to define addresses controlled by more than one private key. Two-of-three for example would mean that any two of a list of three private keys would be required to send coins from this address.

With keys from distinct devices or users, an attacker would have to compromise multiple devices or users at once. Multi signature thus allows to protect against one device catching a virus, one wallet having a backdoor (if the multi signature works across different providers’ wallets), one hardware wallet not being trusted (if hardware wallets can be used for multi signature), etc.

  • There are no good standards yet for multi signature accounts. This might mean that an account that works with one provider’s wallet won’t load in any other wallet which can complicate recovery should that wallet go out of business.
  • Using Multi Signature results in bigger and thus more expensive transactions.
  • Using Multi Signature accounts makes it easier for blockchain analysis companies to follow the trail of a wallet.
  • Multi Signature accounts require backups of additional descriptors, making financial loss from user error more likely.

Why we list it for this wallet

You can set custom scheme to multi-signature accounts (N of M signatures) and create shared accounts on multiple wallets

Source: Website

Unlimited Accounts

Unlimited Accounts

The user can create or restore secondary BTC accounts

  • Accounting: Multiple accounts allow for easier separation of funds.
  • Privacy: Using an account with a positive balance at all time makes it relatively easy for blockchain analysis companies to determine the full history of the wallet. By using multiple accounts, emptying them at times, the user can retain some privacy.

Why we list it for this wallet

You can activate several accounts with different features within the same wallet.

Source: Website

Fingerprint Authentication

Fingerprint Authentication

Fingerprint authentication in Bitcoin wallets enhances security by adding a biometric layer to the access control mechanisms. This feature leverages the unique patterns of a user’s fingerprint to grant access to the wallet, making unauthorized access significantly more difficult. Biometric authentication is generally faster and more convenient than traditional methods like passwords or PINs, as it eliminates the need to remember complex combinations. This form of authentication is particularly useful in mobile wallet applications, where ease of access and security are paramount. Fingerprint authentication minimizes the risk of phishing or brute force attacks that typically target password-based systems. Furthermore, it can be combined with other forms of security measures, like PINs or passwords, to create a multi-factor authentication system for added security. The use of biometric data, however, raises concerns regarding privacy and data security. Users must be assured that their biometric data is stored securely and not vulnerable to unauthorized access or breaches.

  • Enhanced security through a unique, non-replicable form of identification
  • Convenience and speed of access compared to traditional methods
  • Reduced risk of phishing and brute force attacks

Potential privacy concerns and dependency on device hardware capabilities.

Why we list it for this wallet

fingerprint unlock

Source: README

Camera for Secure Transactions

Camera for Secure Transactions

Camera functionality in Bitcoin hardware wallets, represents a significant advancement in wallet security and data transmission. These wallets use their built-in cameras to scan QR codes, enabling a secure and efficient method for data exchange and transaction signing. The camera-based approach is integral to maintaining an air-gapped environment, meaning the wallet does not rely on potentially vulnerable USB or Bluetooth connections for communication. The process involves creating an unsigned transaction as a QR code using a compatible wallet app. This QR code is then scanned by the hardware wallet’s camera. Inside the wallet, the transaction is securely signed using the stored private key. The signed transaction is subsequently displayed as a new QR code on the wallet, which can then be scanned back by the app to broadcast it to the blockchain network. This method of using a camera for QR code scanning and transmission ensures that the private keys remain solely within the hardware wallet, significantly bolstering security against remote attacks. It also enhances privacy, as the wallet does not directly connect to the internet or other devices, thereby reducing exposure to potential vulnerabilities.

  • Enhanced security by maintaining an air-gapped environment
  • Increased privacy as the wallet does not directly connect to the internet
  • User-friendly transaction process with QR code scanning

Why we list it for this wallet

camera and barcode scanner

Source: README

Update: The provider replied to our issue so we took another look.

On Google Play we find no claims of this wallet being non-custodial or open source.

On their website they claim

With Melis you have the complete control of your bitcoins and private keys

which probably means non-custodial. And

Melis is open source, published on GitHub.

but the link only leads us to this GitHub account, not to a GitHub repository. But lets search the appId there … which gives us five hits in this repository.

So this is a Cordova app. The build instructions are there … promising so far. Time to get more hands-on …

$ git clone https://github.com/melis-wallet/melis-cm-client
$ cd melis-cm-client/
$ git log
commit 61246945952eb3c50ef8c7800eba84bea1142836 (HEAD -> release, origin/release, origin/HEAD)
Author: lele <lele@melis.io>
Date:   Thu Jan 2 14:33:58 2020 +0100

    - synced to upstrem 1.5.41

commit 287994f4bcfb08f6ca975ccfb1d12f13c664be3c
Author: lele <lele@melis.io>
Date:   Fri Jan 5 16:29:58 2018 +0100

    - v1.1.0

commit 4dff0ed0b3f75579c7b98f983d87601225324c54 (tag: v1.3.9)
Author: lele <lele@melis.io>
Date:   Fri Jan 5 15:35:25 2018 +0100

    - v1.3.9

commit 653ba15a279b9df2e35c7ce85758b11bc04d0afc
Author: Lele <lele@melis.io>
Date:   Thu Jul 27 16:42:11 2017 +0200

    Provided links to the melis website

commit 11b778e6f8f45d1e4c23c580b8cdc3f7e5ca025f (tag: 0.20.30)
Author: lele <lele@melis.io>
Date:   Thu May 11 09:34:24 2017 +0200

    - public release
$ rgrep "1\.5\.40" .
$ rgrep "1\.5\.41" .
./package.json:  "version": "1.5.41",

So this repository has a total of 5 commits with the latest being ahead of what we would like to reproduce (1.5.40) and the prior one being much behind (1.1.0).

Lets see if the build instructions are helpful:

$ docker run --rm -v $PWD:/mnt --workdir /mnt -it beevelop/cordova bash
root@696ffb01eee2:/mnt# apt update
root@696ffb01eee2:/mnt# apt install -y phantomjs
phantomjs is already the newest version (2.1.1+dfsg-1).
root@696ffb01eee2:/mnt# npm install -g npm bower ember-cli yarn
...
+ ember-cli@3.17.0
+ yarn@1.22.4
+ bower@1.8.8
+ npm@6.14.4
root@696ffb01eee2:/mnt# git --version
git version 2.7.4
root@696ffb01eee2:/mnt# node --version
v10.16.3
root@696ffb01eee2:/mnt# wget https://github.com/melis-wallet/melis-cm-client/releases/download/1.5.1/ember-leaf-theme-basic-master-9601b6f57e468dd0ccc4bbcdb01ae1aebfb0153c.zip
root@696ffb01eee2:/mnt# unzip ember-leaf-theme-basic-master-9601b6f57e468dd0ccc4bbcdb01ae1aebfb0153c.zip
root@8797b57b1bb3:/mnt# mv ember-leaf-theme-basic-master-9601b6f57e468dd0ccc4bbcdb01ae1aebfb0153c ../ember-leaf-theme-basic
root@696ffb01eee2:/mnt# yarn
root@696ffb01eee2:/mnt# bower install --allow-root
root@696ffb01eee2:/mnt# node i18n/generate-melis-i18n.js
root@696ffb01eee2:/mnt# build/cordova-setup.sh
Usage: config <platform> <target>
root@696ffb01eee2:/mnt# build/build-android.sh
Usage: build <target> <version> <keystorepassword>

So with the provider’s help we get a bit further but we still did not manage to get to a compiled app. For build reproduction we would need an unsigned apk. The keystorepassword therefore should not be needed.

Also the zip file being downloaded from the provider’s GitHub is certainly kind of closed source as is and would require investigation apart from how it is cumbersome to use. It would probably be more convenient to provide that folder as a git submodule.

We are looking forward to finally reproducing a build but for now remain with the verdict: not verifiable.

An issue has been opened at https://github.com/melis-wallet/melis-cm-client/issues/1

iPhone

Free and Open Source (FOSS)

Free and Open Source (FOSS)

The wallet’s source code is published under a license approved by the Open Source Initiative (OSI) — such as MIT, GPL, Apache, or AGPL — allowing anyone to inspect, modify, and redistribute it. This is a prerequisite for independent security audits and reproducible builds. Licenses that are merely “source available” but not OSI-approved (e.g., those with Commons Clause restrictions, commercial use prohibitions, or other non-free terms) do NOT qualify. Reproducible builds are not sufficient alone.

  • Transparency: Anyone can verify what the code does — including whether it contains backdoors, bugs, or privacy-violating behavior.

  • Community auditing: More reviewers means vulnerabilities are more likely to be found and fixed.

  • Forkability: If the project is abandoned or goes rogue, the community can fork and continue it.

FOSS alone does not guarantee security. The released binary must also be reproducible from the public source to ensure users are actually running the code that was audited.

Why we list it for this wallet

the Melis Wallet itself is completely free and open source under the MIT License

Source: README

Fingerprint Authentication

Fingerprint Authentication

Fingerprint authentication in Bitcoin wallets enhances security by adding a biometric layer to the access control mechanisms. This feature leverages the unique patterns of a user’s fingerprint to grant access to the wallet, making unauthorized access significantly more difficult. Biometric authentication is generally faster and more convenient than traditional methods like passwords or PINs, as it eliminates the need to remember complex combinations. This form of authentication is particularly useful in mobile wallet applications, where ease of access and security are paramount. Fingerprint authentication minimizes the risk of phishing or brute force attacks that typically target password-based systems. Furthermore, it can be combined with other forms of security measures, like PINs or passwords, to create a multi-factor authentication system for added security. The use of biometric data, however, raises concerns regarding privacy and data security. Users must be assured that their biometric data is stored securely and not vulnerable to unauthorized access or breaches.

  • Enhanced security through a unique, non-replicable form of identification
  • Convenience and speed of access compared to traditional methods
  • Reduced risk of phishing and brute force attacks

Potential privacy concerns and dependency on device hardware capabilities.

Why we list it for this wallet

fingerprint unlock

Source: README

Camera for Secure Transactions

Camera for Secure Transactions

Camera functionality in Bitcoin hardware wallets, represents a significant advancement in wallet security and data transmission. These wallets use their built-in cameras to scan QR codes, enabling a secure and efficient method for data exchange and transaction signing. The camera-based approach is integral to maintaining an air-gapped environment, meaning the wallet does not rely on potentially vulnerable USB or Bluetooth connections for communication. The process involves creating an unsigned transaction as a QR code using a compatible wallet app. This QR code is then scanned by the hardware wallet’s camera. Inside the wallet, the transaction is securely signed using the stored private key. The signed transaction is subsequently displayed as a new QR code on the wallet, which can then be scanned back by the app to broadcast it to the blockchain network. This method of using a camera for QR code scanning and transmission ensures that the private keys remain solely within the hardware wallet, significantly bolstering security against remote attacks. It also enhances privacy, as the wallet does not directly connect to the internet or other devices, thereby reducing exposure to potential vulnerabilities.

  • Enhanced security by maintaining an air-gapped environment
  • Increased privacy as the wallet does not directly connect to the internet
  • User-friendly transaction process with QR code scanning

Why we list it for this wallet

camera and barcode scanner

Source: README

Unlimited Accounts

Unlimited Accounts

The user can create or restore secondary BTC accounts

  • Accounting: Multiple accounts allow for easier separation of funds.
  • Privacy: Using an account with a positive balance at all time makes it relatively easy for blockchain analysis companies to determine the full history of the wallet. By using multiple accounts, emptying them at times, the user can retain some privacy.

Why we list it for this wallet

Multi-account

Source: Website

Multi Signature

Multi Signature

Bitcoin allows to define addresses controlled by more than one private key. Two-of-three for example would mean that any two of a list of three private keys would be required to send coins from this address.

With keys from distinct devices or users, an attacker would have to compromise multiple devices or users at once. Multi signature thus allows to protect against one device catching a virus, one wallet having a backdoor (if the multi signature works across different providers’ wallets), one hardware wallet not being trusted (if hardware wallets can be used for multi signature), etc.

  • There are no good standards yet for multi signature accounts. This might mean that an account that works with one provider’s wallet won’t load in any other wallet which can complicate recovery should that wallet go out of business.
  • Using Multi Signature results in bigger and thus more expensive transactions.
  • Using Multi Signature accounts makes it easier for blockchain analysis companies to follow the trail of a wallet.
  • Multi Signature accounts require backups of additional descriptors, making financial loss from user error more likely.

Why we list it for this wallet

multi-signature accounts (N of M signatures)

Source: Website

The Android analysis above applies to the iPhone app too.

An issue has been opened at https://github.com/melis-wallet/melis-cm-client/issues/1

Product page updated by Leo Wandersleb

Community Opinions

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Do your own research

In addition to reading our analysis, it is important to do your own checks. Before transferring any bitcoin to your wallet, look up reviews for the wallet you want to use. They should be easy to find. If they aren't, that itself is a reason to be extra careful.

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