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3
votes
1answer
137 views

Accepting the UUID collision risk based on number of clients

After reading some questions about the probability of UUID collisions it seems like collisions although unlikely, are still possible and a conflict solution is still needed. Therefore I am wondering ...
1
vote
2answers
262 views

Is it okay if we use an arbitrary string as UUID?

I found the tutorial of client (android) and server (pc) bluetooth tutorial from here. But my question is about the UUID. Is that okay if we define it randomly without the proper format? Because I ...
33
votes
2answers
2k views

Strategy for generating unique and secure identifiers for use in a “sometimes offline” web app

I have a web based project that allows users to work both online and offline and I'm looking for a way to generate unique ids for records on the client side. I'd like an approach that works while a ...
0
votes
2answers
188 views

How deterministic are SessionIDs from SHA'd GUIDs?

Assume I'm using the following code to generate pseudo-random sessionID's: sessionID = SHA-512(GENERATE-GUID()) The GUIDs are pretty deterministic, i.e. I see lots of GUIDs with a lot of the same ...
1
vote
1answer
239 views

How unique should a UUID identified object be?

I am working on a fairly large open source project (Drupal) and the next major version will begin to use UUIDs for a lot of things, including configuration objects. If we put UUIDs into the ...
11
votes
2answers
1k views

Why are UUID / GUID's in the format they are?

Globally Unique Identifiers (GUID) are a grouped string with a specific format which I assume has a security reason. A GUID is most commonly written in text as a sequence of hexadecimal digits ...
14
votes
7answers
3k views

How to generate “language-safe” UUIDs?

I always wanted to use randomly generated strings for my resources' IDs, so I could have shorter URLs like this: /user/4jz0k1 But I never did, because I was worried about the random string generation ...
9
votes
8answers
1k views

A good schema to represent integer numbers from 0 to infinity, assuming you have infinite linear binary storage?

I would like a schema to represent integer numbers starting with 0, without any limit (assuming access to infinite linear storage). Here's a schema that can represent numbers from 0 to 255: Use the ...
13
votes
4answers
9k views

UUID collisions

Has anybody done any real research on the probability of UUID collisions, especially with version 4 (random) UUIDs, given that the random number generators we use aren't truly random and that we might ...