Smartphones Are the Safest Devices to Store Cryptocurrency, Samsung Says

Omar Faridi
  • Samsung Electronics says smartphones are the safest device to store cryptocurrency.
  • “Spendable” digital currency can be securely stored on smartphones because of a Trusted Execution Environment (TEE).

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.

CZ Explains How Binance Dealt With Aftermath of $40 Million Theft

On Sunday (May 19), Changpeng Zhao (aka "CZ"), the Co-Founder and CEO of digital asset exchange Binance, told the crypto community what he and his team had been up to since the May 7 security breach that resulted in a theft of over 7,000 BTC from their Bitcoin hot wallet. 

What Happened on May 7?

According to CZ, the hackers involved in the security breach somehow managed to get control over a number of user accounts and structured large withdrawals from these accounts in such a way thay managed not to be detected/noticed by Binance's "pre-withdrawal risk management checks." Their "post-withdrawal risk monitoring system" only noticed something was wrong after the hackers had moved the stolen BTC off of the exchange via a single transaction, at which time it immediately suspended all "subsequent withdrawals." 

At first, the Binance team was not exactly sure what had happened, and so they decided that the safest course of action was for CZ to send out a tweet to say that the "withdrawal servers" were in "unscheduled maintenance mode" while the team was investigating the incident. 

Communication With the Crypto Community

Once the team had confirmed that the exchange had been hacked, information about the security incident was broadcast to the outside world via all of Binance's communication channels (such as Telegram, Twitter, and Medium). 

Since the team could not be sure which user accounts the hackers had access to, it was decided that it would be too risky to allow further withdrawals to be made until the team had the chance to make "significant changes" to the platform (to make it more secure). Binance's announcement on May 8 estimated that the exchange needed to do "a thorough security review" and estimated that this would take about "ONE WEEK," and that during this period, "deposits and withdrawals" would need to "REMAIN SUSPENDED."

By being fully transparent in their communication with Binance users, they were able to receive "tremendous support" from them.

CZ's Periscope AMA Session on May 8

Seeing CZ live put much of the Binance community "at ease." Unfortunately, because CZ had been up all night, he was not in an ideal mental state when he did the AMA. Just before the AMA, his team told him that a Bitcoin Core developer had suggested that it would be technically possible to roll back the single Bitcoin transaction carried out by the hackers by "hugely incentivizing the miners." CZ made the unfortunate mistake of mentioning this "reorg" idea (which he now realizes is a "taboo topic") during the AMA, for which he took a heavy beating (especially from hardcore Bitcoin maximalists) on Twitter (and elsewhere). 

CZ's Mental State Right After Being Told About the Bitcoin Theft

Although he was in a "F***, F***, F***” state" for around 10 seconds, a few moments later, he "began to come to terms with it," and a quick mental calculation told him that the theft of around 7000 BTC (equivalent of around $40 million at the time) could be fully covered by their SAFU fund. Meanwhile, his team had already gone into "War Mode", and their professionalism and support cheered up CZ. 

Support From the Crypto Community

Binance received support from many sources: people defending him and Binance on social media platforms, and helping to answer questions; the Binance Angels (who are all volunteers) "addressing questions" and "reassuring" users on "multiple communities"; analytics firms helping with the tracking of the stolen funds; exchanges and wallet services offering to help by blocking "any deposits associated with the hacker addresses"; and "numerous offers for help from law enforcement agencies around the world."

A Blessing in Disguise?

"Speaking with various team members, and as correctly analyzed by community members, such as Gautam Chhugani, this incident may actually be a good thing for us in the long run. Security is a never-ending practice. There are always more things to do in security, and we have implemented many of them in this last week and will continue to implement more in the future. Given this incident, Binance has actually become far more secure than before, not just in the affected areas, but as a whole."