Mapping arbitrary strings to hashes of 10 character length - time to crack it and collision probability [duplicate]

Question

I would like to map strings of arbitrary length to hashes of 10 character length.

The length of the alphabet is of 64 characters (0-9, A-Z, a-z, _, -).

Obviously 2 same strings must produce the same hash.

I have the following doubts:

1. With 64 characters and a hash length of 10 characters I have a number of combination of 64^10 = 1,15*10^18. How long would it require for a modern computer to crack it?

2. To guarantee that 2 same strings produce the same hash I was thinking to apply a SHA function to the string and then truncate the output to 60 bits (64 = 2^6). In this case, which SHA function should I use and why? And what's the collision probability in such case?

Answer 1

1. Not possible to calculate unless we know the difficulty of the hash.

2. A hash function is deterministic, so the same string will always return the same output. For outputting 60 bits, you could use any hash function that have more than 60 bits on the output.