Follow Slashdot stories on Twitter


Forgot your password?

Comment Re:Breakable encryption != no encryption (Score 1) 441

There was a programming contest at the campus one guy, who won, came up with just 231 bytes implementation of One-Time-Pad.

231 bytes sounds about right for what amounts to loop with a handful of instructions in it.

I assume it was either in assembler or he had a very space-efficient compiler/linker and I/O instruction calls were negligible in size.

Comment Re: Breakable encryption != no encryption (Score 2) 441

There is no such thing as unbreakable encryption.

A one-time pad, properly implemented, is by definition unbreakable.

Why? Because any given encrypted text, say,

can be created from any arbitrary same-length input given a specifically crafted key.

In other words, if I'm a prosecutor trying to convince a naive jury that the message above is "KillPresident..." I can come up with a key that will "prove" my point. Likewise, the defense can come up with a key that makes the same encrypted message say "PrezIsGreat!..."

Comment Breakable encryption != no encryption (Score 2, Informative) 441

If encryption is breakable with a large amount of effort, then it does several useful things:

* It prevents people without the resources from accessing your mail.
* It may provide short-term security, which may be sufficient.
* It makes those who do have the resources be selective in whose encryption they break.

For example, if it takes a minimum of a week to break the encryption on an encrypted web connection that discusses an embargoed news item that will be published in 6 days, that's good enough.

Another example: If a government wants to crack down on encrypted communications among drug traffickers, but it costs them $10,000,000 for each decryption effort, they will need to pick and choose who they go after.

There are encryption systems that are provably unbreakable without a key, such as a one-time pad. Unfortunately, they are usually not practical to implement correctly.

Comment Not a "toy" (Score 1) 116

It's a bona fide low-power computer that is suited for some computing tasks but is not a replacement for a laptop or desktop PC.

There is a difference.

Comparing a PC to a Pi is like comparing a professional-grade bicycle with a $50 kid's bike. Both get the job done and both are built to last for years, but one has a lot more features than the other.

It is NOT comparing a professional-grade bicycle with a toy bicycle that Ken and Barbie dolls can ride around on.

Comment Why Bitcoin will fail (Score 1) 267

Cryptocurrencies may succeed, but Bitcoin has too many limitations in it that newer cryptocurrencies don't have. In the long run, this will doom BC unless it makes significant changes.

In the short run, political forces like in South Korea and the high transaction costs will push it down. I don't see it crashing below January 2017 levels any time soon, but it will be below $5000 by the end of the decade.

The one thing it does have is market dominance and relatively wide acceptance.

The future of cryptocurrencies will be in:
1) Bank/government/other-big-corporation-backed currencies
2) A cryptocurrency that is what Bitcoin was in the beginning - a hard-to-track, very-low-transaction-cost currency that doesn't give people with special equipment a significant advantage.

The one thing that may hamper 2) is if mining is concentrated in one part of the world due to cheap energy. That can lead to cartels and loss of trust as a "nearly anonymous" medium of exchange.

Comment Death+70 years gives certainty to PD status (Score 1) 275

Besides government works and works whose copyrights are challenged in court ("Happy Birthday to You" etc.), works not "for hire" published after 1923 and whose only author died 70 years ago have entered into the public domain when the 70th anniversary arrives, if they weren't already in the public domain.

In almost all cases, they would have already entered due to non-renewal or other reasons.

It's not much, I know. I can't think of any specific examples off the top of my head.

This is important though in that it removes any UNCERTAINTY about a work's copyright status. For example, if a book was published in 1924-1947 and the author died in 1947 and there isn't some reason the (c) last longer than "70 years after the death of the author," we know it's now in the public domain. A week ago, unless we did a diligent search for renewals, we did not know.

Slashdot Top Deals