[CASSANDRA-11518] o.a.c.utils.UUIDGen clock generation is not very high in entropy

• Type: Improvement
• Status: Resolved
• Priority: Low
• Resolution: Fixed
• Fix Version/s: 3.0.7, 3.7
• Component/s: Legacy/Core
• Assignee: Ariel Weisberg
• Reporter: Ariel Weisberg

Authors

Ariel Weisberg

Reviewers

Branimir Lambov

• Created: 06/Apr/16 19:06
• Updated: 16/Apr/19 09:30
• Resolved: 05/May/16 22:09

Description

makeClockSeqAndNode uses java.util.Random to generate the clock. Random only has 48-bits of internal state so it's not going to generate the best bits for clock and in addition to that it uses a collision prone seed that sort of defeats the purpose of clock sequence.

A better approach to get the most out of those 14-bits would be to use SecureRandom with something like SHA1PRNG.