Question

I need to generate unique ids for my application and I am looking for suitable algorithms. I would prefer something like this —

YYYY + MM + DD + HH + MM + SS + <random salt> + <something derived from the preceding values>

F.ex. –

20100128184544ewbhk4h3b45fdg544

I was thinking about using SHA-256 or something but the resultant string should not be too long. I could use UUID but again, they are too long and they are guaranteed to be unique on only one machine.

I would welcome suggestions, ideas. My programming language is Java.

Edit: The ids need not be cryptographically secure. I am looking at simpler hashing algos like the one by Dan Bernstein, etc.

Answer 1

So I have finally settled for this –

d = YYYYMMDDHHMMSS
hash = d + sha256(d + random_salt)[:10]

Thank you all for the response.