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An example: low outcome, or expectation in terms of game theory, can be the reason for a class of adversaries that are neither probabilistic quasi-polynomial nor PPT, and would only go after polynomial-logarithmic-time targets.


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For private key operations you need at least $n$ (the modulus) and $d$ (the private exponent). The primes $p$ and $q$ let you calculate those – or use some shortcuts for quicker computation – so they also suffice. In practice RSA keys often include all of those values, to avoid having to compute them as needed and to allow for optimized and unoptimized ...


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Yes, the basic idea of hardcoding a public key is secure. It is sometimes recommended as an alternative to the complexity TLS and PKI bring – otherwise it can be easy to skip a crucial step and end up with little or no security. However, the "encrypt a secret for server" scheme has some weaknesses compared to TLS. The clearest is lack of forward secrecy ...


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Is it safe to recreate the key pair using the password+salt every time I need to use it so I don't have to store the keys (encrypted or not) anywhere in the system? The problem with that is that your public key then effectively becomes a password hash, meaning anyone who sees it will be able to mount a dictionary attack on your password to generate the ...


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The security - assuming you can validate the correctness of $K$ - is 56 bits (not even counting any attacks on DES itself, assuming to test all keys). This is because you can brute force $K_{BT}$ without even looking at $K_{AT}$ in your particular scheme. 2 key triple DES on the other hand would at least offer over 80 bit security. So this scheme is ...


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There can be much simpler methods than CM for group orders of a specific form. For exemple if $p \equiv 2 \pmod 3$ and $b \not\equiv 0 \pmod p$, the curve $Y^2 = X^3 + b$ over $\mathbf{F}_p$ has $p+1$ points. (The proof of this is easy and left as an exercise.) Such methods are also used to easily construct "good enough" pairing-friendly curves. As Thomas ...


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There is a method known as "Complex Multiplication". However, it is not simple at all, and tends to be overly expensive for most target orders. See this article for some details. There is also the (theoretical) concern that a curve constructed that way may have a special structure though could possibly be leveraged into an attack one day; generally speaking, ...


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Regarding the 3rd part of your question, "Can and should ordinary, run of the mill elections be conducted online ..." - If one thinks of an election as a problem around the issue of preserving the privacy of many inputs (a people or population's votes) while correctly producing the right result (i.e. correctly tabulating the outcome of the election) and ...


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Basically RSA signatures work just like encryption but with the keys exchanged. If somebody tells you $m^{sk}$ you can easily test if $$ (m^{sk})^{pk} \equiv m\ (mod\ N) $$ but you cannot calculate $m^{sk}$ yourself. The problem/trick is the usual, exponentiation is easy but logarithm is hard. (I like using $sk$/$pk$ for secret-/public-key rather than ...


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OK, so... The solution I have found, which satisfies exactly what I've been searching for, is based on OpenSSL. I have initially discovered and tested it through the PHP function openssl_private_encrypt (and equivalent openssl_public_decrypt). Since my goal was to implement this in .net project I'm working on, I have ended up with OpenSSL.Net wrapper for C# ...


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I would explore the GPU option before spending money on specialized hardware. I have done something similar using CUDA where I was doing many ECC operations in parallel. The GPU was about 30x - 50x faster than the CPU. You could probably hash the data on the CPU and then use the GPU for the RSA exponentiation.


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As far as I know, unknow key-share (UKS) attacks are mostly related to key exchange protocols. Presentation An UKS attack on an authenticated key exchange (AKE) protocol is an attack whereby an entity $A$ ends up believing he shares a key with entity $B$,and although this is in fact the case, $B$ mistakenly believes the key is instead shared with an ...


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I will give you the simplified answer. The public key encryption does not prevent adversery from computing private key from public key. It just makes it very very very hard. The algorithms use math that allows simple private->public calculation, but public->private has no good mathematical "shortcuts". It would take adversery more time to calculate this, ...


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Yes, (asymmetric) encrypt-then-sign would provide the same properties as (symmetric) encrypt-then-mac. It would provide integrity and authenticity of the ciphertext. It is however possible for another person to re-sign the encrypted message if encrypt-then-sign is used. This is a problem when other parties are trusted within the same network. Note as well ...


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There is typically no private key on the client side. At a high level the process goes something along the lines of (this is a simplification, read the protocol specs if you want the fine details) The client sends the server a "hello" message with info on supported protocols and ciphersuites. The server chooses a cipersuite and protoocol version and sends ...


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While there are many TLS configurations, I will describe the most common setup. The public key is fixed on the server side - it is the servers public key. Upon connecting to the server and receiving the public key, the client then validates the key by checking that it has not expired, that it matches the domain name of the server who sent it, and most ...



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