## Mining Bitcoin With Pencil and Paper what is the bitcoin price

A cryptographic hash function takes a block of input data and creates a smaller, unpredictable output. The hash function is designed so there’s no short cut to get the desired output—you just have to keep hashing blocks until you find one by brute force that works. For bitcoin, the hash function is a function called SHA-256. To provide additional security, bitcoin applies the SHA-256 function twice, a process known as double-SHA-256.

In bitcoin, a successful hash is one that starts with enough zeros.

[1] just as it is rare to find a phone number or license plate ending in multiple zeros, it is rare to find a hash starting with multiple zeros. But bitcoin is exponentially harder. Currently, a successful hash must start with approximately 17 zeros, so only one out of 1.4×10 20 hashes will be successful.**What is the bitcoin price**

The following diagram shows a

Block in the bitcoin blockchain along with its hash. The yellow bytes are hashed to generate the block hash. In this case, the resulting hash starts with enough zeros so mining was successful. However, the hash will almost always be unsuccessful. In that case, the miner changes the nonce value or other block contents and tries again.

In contrast, litecoin, dogecoin, and similar altcoins use the

Scrypt hash algorithm, which is intentionally designed to be difficult to implement in hardware. It stores 1024 different hash values into memory, and then combines them in unpredictable ways to get the final result. As a result, much more circuitry and memory is required for scrypt than for SHA-256 hashes.**What is the bitcoin price** you can see the impact by looking at mining hardware, which is thousands of times slower for scrypt (litecoin, etc) than for SHA-256 (bitcoin). Conclusion

The SHA-256 algorithm is surprisingly simple, easy enough to do by hand. (the elliptic curve algorithm for signing bitcoin transactions would be very painful to do by hand since it has lots of multiplication of 32-byte integers.) doing one round of SHA-256 by hand took me 16 minutes, 45 seconds. At this rate, hashing a full bitcoin block (128 rounds)

[3] would take 1.49 days, for a hash rate of 0.67 hashes per day (although I would probably get faster with practice). In comparison, current bitcoin mining hardware does several terahashes per second, about a quintillion times faster than my manual hashing. Needless to say, manual bitcoin mining is not at all practical. [5]

**what is the bitcoin price**

[2] the source of the constants used in SHA-256 is interesting. The NSA designed the SHA-256 algorithm and picked the values for these constants, so how do you know they didn’t pick special values that let them break the hash? To avoid suspicion, the initial hash values come from the square roots of the first 8 primes, and the

K t values come from the cube roots of the first 64 primes. Since these constants come from a simple formula, you can trust that the NSA didn’t do anything shady (at least with the constants).

[3] unfortunately the SHA-256 hash works on a block of 512 bits, but the bitcoin block header is more than 512 bits. Thus, a second set of 64 SHA-256 hash rounds is required on the second half of the bitcoin block. Next, bitcoin uses

Double-SHA-256, so a second application of SHA-256 (64 rounds) is done to the result.**What is the bitcoin price** adding this up, hashing an arbitrary bitcoin block takes 192 rounds in total. However there is a shortcut. Mining involves hashing the same block over and over, just changing the nonce which appears in the second half of the block. Thus, mining can reuse the result of hashing the first 512 bits, and hashing a bitcoin block typically only requires 128 rounds.

[4] obviously I didn’t just have incredible good fortune to end up with a successful hash. I started the hashing process with a block that had already been successfully mined. In particular I used the one displayed earlier in this article,

A cryptographic hash function takes a block of input data and creates a smaller, unpredictable output. The hash function is designed so there’s no short cut to get the desired output—you just have to keep hashing blocks until you find one by brute force that works.**What is the bitcoin price** for bitcoin, the hash function is a function called SHA-256. To provide additional security, bitcoin applies the SHA-256 function twice, a process known as double-SHA-256.

In bitcoin, a successful hash is one that starts with enough zeros.

[1] just as it is rare to find a phone number or license plate ending in multiple zeros, it is rare to find a hash starting with multiple zeros. But bitcoin is exponentially harder. Currently, a successful hash must start with approximately 17 zeros, so only one out of 1.4×10 20 hashes will be successful. In other words, finding a successful hash is harder than finding a particular grain of sand out of all the grains of sand on earth.

The following diagram shows a

Block in the bitcoin blockchain along with its hash. The yellow bytes are hashed to generate the block hash.**What is the bitcoin price** in this case, the resulting hash starts with enough zeros so mining was successful. However, the hash will almost always be unsuccessful. In that case, the miner changes the nonce value or other block contents and tries again.

In contrast, litecoin, dogecoin, and similar altcoins use the

Scrypt hash algorithm, which is intentionally designed to be difficult to implement in hardware. It stores 1024 different hash values into memory, and then combines them in unpredictable ways to get the final result. As a result, much more circuitry and memory is required for scrypt than for SHA-256 hashes. You can see the impact by looking at mining hardware, which is thousands of times slower for scrypt (litecoin, etc) than for SHA-256 (bitcoin). Conclusion

The SHA-256 algorithm is surprisingly simple, easy enough to do by hand. (the elliptic curve algorithm for signing bitcoin transactions would be very painful to do by hand since it has lots of multiplication of 32-byte integers.) doing one round of SHA-256 by hand took me 16 minutes, 45 seconds.**What is the bitcoin price** at this rate, hashing a full bitcoin block (128 rounds)

[3] would take 1.49 days, for a hash rate of 0.67 hashes per day (although I would probably get faster with practice). In comparison, current bitcoin mining hardware does several terahashes per second, about a quintillion times faster than my manual hashing. Needless to say, manual bitcoin mining is not at all practical. [5]

[2] the source of the constants used in SHA-256 is interesting. The NSA designed the SHA-256 algorithm and picked the values for these constants, so how do you know they didn’t pick special values that let them break the hash? To avoid suspicion, the initial hash values come from the square roots of the first 8 primes, and the

K t values come from the cube roots of the first 64 primes. Since these constants come from a simple formula, you can trust that the NSA didn’t do anything shady (at least with the constants).**What is the bitcoin price**

[3] unfortunately the SHA-256 hash works on a block of 512 bits, but the bitcoin block header is more than 512 bits. Thus, a second set of 64 SHA-256 hash rounds is required on the second half of the bitcoin block. Next, bitcoin uses

Double-SHA-256, so a second application of SHA-256 (64 rounds) is done to the result. Adding this up, hashing an arbitrary bitcoin block takes 192 rounds in total. However there is a shortcut. Mining involves hashing the same block over and over, just changing the nonce which appears in the second half of the block. Thus, mining can reuse the result of hashing the first 512 bits, and hashing a bitcoin block typically only requires 128 rounds.

[4] obviously I didn’t just have incredible good fortune to end up with a successful hash. I started the hashing process with a block that had already been successfully mined.**What is the bitcoin price** in particular I used the one displayed earlier in this article,