Never use a pseudorandom number generator to create keys

[NotATether]

You should never, ever use a PRNG (pseudorandom number generator) when you are creating a wallet seed phrase, private key, or extended private key. Here is why:

PRNGs use a deterministic sequence to generate the numbers. Most PRNGs are seeded with a combination of process ID and the current date/time in unix timestamp format. Some are even worse and just leave the seed at zero or some other constant. This is very bad for security because it means attackers can guess the key from a limited number of inputs. So instead of 2^256 guesses as it's supposed to be, you're now looking at something like 86400 (in case you only know the day) times 3,000,000 (on Linux process IDs can get really large for long-running systems, on shorter-uptime systems or on Windows they can be even smaller) times like 5 or 10 in case the RNG was called that many times.

As you can see, this is easily calculated on a GPU, and will result in stolen funds once the private key is discovered.

[ABCbits]

Some reader might find it's crazy that it already happen few times on cryptocurrency world. For example, that's how wallet generated older version of Trust Wallet[1] and wallet generated with bx[2] got hacked

[1] https://nvd.nist.gov/vuln/detail/CVE-2024-23660
[2] https://milksad.info/

[bitmover]

You should never, ever use a PRNG (pseudorandom number generator) when you are creating a wallet seed phrase, private key, or extended private key. Here is why:

PRNGs use a deterministic sequence to generate the numbers. Most PRNGs are seeded with a combination of process ID and the current date/time in unix timestamp format. Some are even worse and just leave the seed at zero or some other constant. This is very bad for security because it means attackers can guess the key from a limited number of inputs. So instead of 2^256 guesses as it's supposed to be, you're now looking at something like 86400 (in case you only know the day) times 3,000,000 (on Linux process IDs can get really large for long-running systems, on shorter-uptime systems or on Windows they can be even smaller) times like 5 or 10 in case the RNG was called that many times.

As you can see, this is easily calculated on a GPU, and will result in stolen funds once the private key is discovered.

I think bitaddress.org illustrates this very well.
It uses your mouse movements to generate extra randomness, showing how important it is not to rely in simple PRNGs techniques.

It is always better to use specific software for generatingyour wallet, such as electrum.

[examplens]

You should never, ever use a PRNG (pseudorandom number generator) when you are creating a wallet seed phrase, private key, or extended private key. Here is why:

PRNGs use a deterministic sequence to generate the numbers. Most PRNGs are seeded with a combination of process ID and the current date/time in unix timestamp format. Some are even worse and just leave the seed at zero or some other constant. This is very bad for security because it means attackers can guess the key from a limited number of inputs. So instead of 2^256 guesses as it's supposed to be, you're now looking at something like 86400 (in case you only know the day) times 3,000,000 (on Linux process IDs can get really large for long-running systems, on shorter-uptime systems or on Windows they can be even smaller) times like 5 or 10 in case the RNG was called that many times.

As you can see, this is easily calculated on a GPU, and will result in stolen funds once the private key is discovered.

I think bitaddress.org illustrates this very well.
It uses your mouse movements to generate extra randomness, showing how important it is not to rely in simple PRNGs techniques.

It is always better to use specific software for generatingyour wallet, such as electrum.

Honestly, I've always seen things like this as entertainment and maybe some kind of education. It is not a serious final solution, especially not for storing digital assets.

[bitmover]

Honestly, I've always seen things like this as entertainment and maybe some kind of education. It is not a serious final solution, especially not for storing digital assets.

I agree. This is just an illustration.

The only secure way to store your asseets is a hardware wallet imo.

If you are computer genius, you can use other methods like an airgapped computer. I lack that knowledge and experience

[dkbit98]

You should never, ever use a PRNG (pseudorandom number generator) when you are creating a wallet seed phrase, private key, or extended private key.

I was trying to warn about this few years ago when I explored TRNG and found the difference compared with PRNG.
Basically PRNG can be reproduced and cracked easily, that is like having a backdoor for your keys.
I could be wrong but I suspect that some bitcoin wallets could still be using PRNG for generating keys. 

[bitmover]

I could be wrong but I suspect that some bitcoin wallets could still be using PRNG for generating keys. 

This is why we should never trust a lot of money in closed source wallets, or wallets which as new and not tested by the community for a long time.

I like to keep a few bucks in my phone. I use now Aqua and Exodus, which I know aren't the best wallets, but they are convenient and I only hold  small amounts.

[dkbit98]

I like to keep a few bucks in my phone. I use now Aqua and Exodus, which I know aren't the best wallets, but they are convenient and I only hold  small amounts.

They are fine for using with small amounts when you need to send or receive payment urgently.
I know some people wanted to invent the wheel again so they used dices to generate seed words for their wallet but they generated very weak entropy, and that is worse than using PRNG.
Another fun fact is that most computers, laptops and many smartphones use software-based PRNG, so think about that

[ABCbits]

Another fun fact is that most computers, laptops and many smartphones use software-based PRNG, so think about that

While OS usually offer CSPRNG, where CS stands for Cryptographically Secure. But unless you use open-source wallet and actually inspect the code, who knows if your wallet actually use that. And not all CSPRNG are equal.

[dkbit98]

While OS usually offer CSPRNG, where CS stands for Cryptographically Secure. But unless you use open-source wallet and actually inspect the code, who knows if your wallet actually use that. And not all CSPRNG are equal.

I think it's best to listen Edward Snowden, and he is saying that most of the stuff we consider Cryptographically Secure have integrated secret backdoors in them.
Knowing that I am very careful saying that anything is secure, unless it has open source code that can be inspected.
Everyone knows that most processors have backdoors also...

[ABCbits]

While OS usually offer CSPRNG, where CS stands for Cryptographically Secure. But unless you use open-source wallet and actually inspect the code, who knows if your wallet actually use that. And not all CSPRNG are equal.

I think it's best to listen Edward Snowden, and he is saying that most of the stuff we consider Cryptographically Secure have integrated secret backdoors in them.
Knowing that I am very careful saying that anything is secure, unless it has open source code that can be inspected.
Everyone knows that most processors have backdoors also...

Yeah, i'm aware of Snowden's report. But IMO /dev/urandom (on popular Linux or BSD based OS) is secure enough for most people and it uses various input (CPU is just one of the input source) to generate random binary.

[dkbit98]

Yeah, i'm aware of Snowden's report. But IMO /dev/urandom (on popular Linux or BSD based OS) is secure enough for most people and it uses various input (CPU is just one of the input source) to generate random binary.

Not really, unless they are using additional encryption, open source bios, and if your computer is offline and not connected to the internet.
Almost everything should be considered compromised now, especially modern smartphones with stock android and iOS operating systems.
Most people are not targets yet, but I think they will become soon, maybe in next 5 to 6 years.

[bitmover]

Yeah, i'm aware of Snowden's report. But IMO /dev/urandom (on popular Linux or BSD based OS) is secure enough for most people and it uses various input (CPU is just one of the input source) to generate random binary.

Not really, unless they are using additional encryption, open source bios, and if your computer is offline and not connected to the internet.
Almost everything should be considered compromised now, especially modern smartphones with stock android and iOS operating systems.
Most people are not targets yet, but I think they will become soon, maybe in next 5 to 6 years.

Smartphones are really compromised, just like windows and Mac computers.

There is so much stuff installed in those devices that it is almost impossible to have security and privacy.

But I think it is possible to create secure environments inside those devices, using stuff such as a hardware wallet.

[dkbit98]

But I think it is possible to create secure environments inside those devices, using stuff such as a hardware wallet.

You can certainly make them better than they are.
Flashing this devices with alternative open source operating systems like GrapheneOS, LineageOS or DivestOS would be the first step.
There is also cheap devices like Maix Amigo that can work great as signing devices and they work similar like hardware wallets.