The fastest altcoins; Blocks in less than 30 seconds.

[Revelation 22:13]

Memecoin: 30-second blocks

Digitalcoin: 20-second blocks

Worldcoin: 15-second blocks

Fastcoin: 12-second blocks

Flashcoin: 6-second blocks

How fast can we get before it stops working altogether?

[Foxpup]

Not very. Fast confirmation times do not improve security at all (assuming equal difficulty, one 10-minute block is as secure as thirty 20-second blocks), and in fact security is reduced significantly by wasting hashpower on more orphaned blocks since network lag is a much bigger factor. The result is that it is possible to do a 51% attack with significantly less than 51% of the hashpower, if the attacker can maintain a low-latency connection to many nodes.

[Revelation 22:13]

Not very. Fast confirmation times do not improve security at all (assuming equal difficulty, one 10-minute block is as secure as thirty 20-second blocks), and in fact security is reduced significantly by wasting hashpower on more orphaned blocks since network lag is a much bigger factor. The result is that it is possible to do a 51% attack with significantly less than 51% of the hashpower, if the attacker can maintain a low-latency connection to many nodes.

Besides that, how fast can blocks be while still having a stable blockchain?

[jeannie]

I think Flashcoin nearly reach the limit.   Can't imagine anything faster than that.

[Revelation 22:13]

Are there any faster coins I haven't listed?

[muddafudda]

Memecoin is 30 second blocks, 12 1/2 minute confirms, just nice (25 blocks).

Deliberately kept it up for reasons listed.

[Revelation 22:13]

Added.

[ezcoin]

Although I think smaller block times are possible, there's the problem of the block chain growing too quickly. For that reason I chose 60 seconds for EZCoin. Personally I think it is a nice balance.

[Praxis]

Isn't Worldcoin 15s?

[Revelation 22:13]

Isn't Worldcoin 15s?

Added.

[Liquid]

+1 to this thread im all for testing the limits of cryptocurrency in any way possible