Samsung Electronics, one of the world’s largest smartphone manufacturers, recently stated in an official blog post that mobile-based crypto wallets are the best and safest option for cryptocurrency “short-term and medium-term storage.”

The post explains that smartphone-based cryptocurrency wallets are a fairly secure place to hold digital “spending money,” equivalent to the amount of fiat one would keep in a physical wallet. For storing cryptocurrency on a long-term basis, Samsung recommended creating several backups of the private key associated with crypto wallets.

Offline Storage Preferred

The smartphone maker added that private keys should be stored offline to maximize security, which means they should not reside on a mobile phone or any other device regularly connected to the internet. Samsung added that private keys are to be kept in cold storage (offline) to maximize protection.

Samsung’s blog post argues that smartphone-based crypto wallets are the safest place to store “spendable” cryptocurrency because of a mobile phone feature called Trusted Execution Environment (TEE). The TEE runs in its own independent execution environment, which means that its random-access-memory (RAM) and persistent storage (usually a hard-drive) are separate from a smartphone’s main operating system.

Due to a separate run-time environment, the Android OS can’t directly access the TEE, even if the operating system has been hacked. Moreover, the TEE can only be accessed via an application programming interface (API), Samsung’s blog notes.

The smartphone manufacturer refers to the small-sized apps in the TEE as “trustlets” and notes that all reliable mobile-based cryptocurrency wallets restrict and control access to users’ private keys by keeping them in seemingly impenetrable trustlets.  Per Samsung , this helps ensure “security is seriously tight,” as it’s nearly impossible for malware to reach private keys stored this way.

Vulnerabilities Still Exist

The smartphone company added that its Samsung Knox platform’s TEE provides an even greater level of security. It warned that since TEE hardware is not available on laptop and desktop computers, the private keys stored in these devices may be easily compromised.

Despite the high level of security TEEs offer, Samsung claims a novice programmer can potentially make the mistake of designing a crypto wallet that stores private keys on a smartphone’s hard drive, making it vulnerable to hackers. Moreover, wallets themselves can be infected with malware on purpose.

Interestingly, Samsung’s blog post comes shortly after Ethereum wallet interface MyEtherWallet released a ‘hardware wallet’ app beta for iOS , which it claims could give users the same security cold-storage solutions do.