remcob

24 ms·

181.
by remcob 9y ago
Around when this was published I looked into the feasibility of pencil-and-paper wallets. What would it take to generate a key-pair using just pencil and paper? There are tricks like big tables of precomputed multiples of the generator that
182.
by remcob 9y ago
Solidity is a complex moving target with limitations such as max 16 local variables, missing optimizations and only partial support for dynamic allocation. You might want to compile directly to EVM instead of through Solidity. The EVM is ve
183.
by remcob 9y ago
I always wondered how distributed systems like Spanner/TrueTime would scale when we build a datacenter on Mars. Mars-Earth round-trip-times are in the order of minutes. We are lucky that earthbound round-trip-times are nearly impercept
184.
by remcob 9y ago
This has been done! At least, as a joke. Back in the dot-com bubble the financial website IEX.nl announced an April first IPO for 'F/rite Air' (fried air). They received a significant sum in offers… Source: https:/&#x2
185.
by remcob 9y ago
The explanation for bitwise complement ignores the word-size which matters a lot here. For example ~4 = 251 in uint8, not 3 like in the example.
186.
by remcob 9y ago
Ethereum doesn't use UTXO like Bitcoin, so there is no inherent need to spend from multiple accounts. If you still want to do so, it's easy to write some smart contracts that allow you to do this. I don't see the use-case tho
187.
by remcob 9y ago
As someone who has worked with ETH, I tend to disagree. If there are issues with Ethereum, they mostly stem from it being ahead of other blockchains in terms of features. With that I mean that other blockchains don't have these issues
188.
by remcob 9y ago
From the name and the title, I was hoping it would be a prototype blockchain based distributed consensus extensions for Postgres. I have to admit that I was a little bit disappointed to discover that it is a collection of transaction parsin
189.
by remcob 9y ago
In the interest of said discussion, I would appreciate a write-up of the rationale behind the approach chosen, when you are ready. It could help others that are in a similar situation. Perhaps inspire a better practice in the industry.
190.
by remcob 9y ago
I'm so looking forward to this post!. hp-FEM methods, in particular, caught my attention, they look so promising. Do they work in practice? Some time ago I was trying to make a 'hpq-FEM' using rational functions as a basis, l
191.
by remcob 9y ago
I assume you're joking. Nevertheless, for missiles, it's more about detecting and correcting early when the error is still manageable. If you go at Mach something, a few meters off course can quickly become a few hundred.
192.
by remcob 9y ago
(I did not downvote, you raised a valid point that I responed too. Though your postsounded a bit like the "I have nothing to hide" argument, which has been debunked many times before.) Currently the easiest way to regulate is at t
193.
by remcob 9y ago
This approach is propably fine for small one-off transactions, but: * Anonymous cash is difficult and illegal to scale. * 'private sites' can not be trusted (they will be subpoenaed, hacked, wiretapped, etc.). * Sellers will learn
194.
by remcob 9y ago
> It's not impossible, it's just annoying. Indeed it is not impossible. It does requires a tremendous amount of expert knowledge. (And people with such knowledge usually have successful careers not requiring this sort of privac
195.
by remcob 9y ago
A year ago I was doing a very similar analysis using both the 2011 and 2014 leaked databases. They are publicly available (won't post a link, but I'm sure you can find it). My interest was in the privacy aspects of bitcoin. Beside
196.
by remcob 9y ago
Quite the opposite actually, if you're a citizen of it you have some constitutional protection against your own government spying on you, at least in the U.S. AFAIK. If you are outside of it, you're fair game.
197.
by remcob 9y ago
Yeah, it looks like the choices are between competent+PRISMed and incompetent. The former can likely only be accessed by the Five-Eyes. The latter may be secure, but may also be insecure and accessed by anyone. What would you bet on? For me
198.
by remcob 9y ago
This is where I would mention that I'm running Cyanogemod, rooted of course, with Protect My Privacy (PMP) installed. http://www.android.protectmyprivacy.org/ While I really like non-Google Android + PMP in theory, the
199.
by remcob 9y ago
You can choose non-US companies. OnePlus, Samsung, etc. I don't think China or S.Korea is less inclined to spy on you, but I suspect they are less competent at it.
200.
by remcob 9y ago
> 45-50°C below the ambient air temperature That's incredible! Isn't that enough to run a heat engine on? If so, does this allow you to extract (nearly) free energy out of the ambient heat?
201.
by remcob 9y ago
Ikea, at least at the time, had very affordable fridges with A++ and A+++ energy certification. I trusted the energy certification, and assumed name-brands had no significant advantage over white-labeled (since it's all Chinese import
202.
by remcob 9y ago
When I bought a fridge some years ago, the capital cost of a new fridge was about €100, the annual operating cost was about €50. Investing in a more efficient fridge pays of quickly. Second hand fridges (€50 capital, €80 operating) made no
203.
by remcob 9y ago
> Using Popper 1956’s famous mechanical wave example as an analogy, throwing a rock into a pond so that waves on the surface spread out into the future requires every bit the conspiracy that is needed for waves to converge on a point in
204.
by remcob 9y ago
In which use cases is the asymptotic cycles per byte relevant compared to the small case performance? I mostly use hashes as part of signing/verifying small messages, say an 80 byte JWT, a Blockchain transaction, a certificate, an TLS&
205.
by remcob 9y ago
I made this factorial compile-and-run example in NodeJS: https://gist.github.com/Recmo/e0b6911992897c5f51c38fda822537... To run it you need at least Node 8.0.0 and the `--expose-wasm` flag. Sorry for using modern JS, y
206.
by remcob 9y ago
With a sponge construction the AEAD is a one-pass operation. You feed plaintext in, out comes ciphertext. In the end you crank it one more time and out comes the MAC/tag. This is unlike other constructions, where you need to go over th
207.
by remcob 9y ago
A rotate operation is invertible, a logic shift by itself is not. Another fun one is x ^= x >> n with n some strictly positive constant, this is also invertible. It's used a lot in the murmurhash family of non-cryptograhic hash f
208.
by remcob 9y ago
You can, and you just invented the Sponge construction in the process! :) The key idea is to only expose part of the state to inputs/outputs.
209.
by remcob 9y ago
Yes, I'm much more rooting for the Sponge construction than Keccak/SHA3 specifically. I'd like to see any permutation function get broad hardware support. > I think there's wide agreement that SHA-3 is too conservativ
210.
by remcob 9y ago
True, the symmetric primitives are sort of interchangeable, but I'd like to see how to build an AEAD using hash functions that doesn't require you process the data twice. I don't think it can be easily done, if at all. It cer

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