# What is Hash Function in Cryptocurrency?

The kind of encryption used in blockchain is called a hash function. Hash Function is one-way encryption without a key. What this means is, if, for example, you put the line “What is bitcoin mining?” through movable type’s SHA-256 cryptographic hash algorithm you get the hash value 724b3e1c2da8c82822f137f95f6373369d14c45396c58b754e29ca36c8250db4.

Now the interesting thing about hash functions is that any change in the original input causes a completely different hash value to be made. This randomness ensures that predicting the output is impossible.

So even if the input is “What is bitcoin mining”, the hash value changes to 7337ce9d8bfa81a71aacbe1da7f5b73a39dbcedb033712fb3d0bf5da737d2741. Despite the only change being the lack of a question mark, the hash value changes completely.