138 reputation
14
bio website xs4all.nl/~itsme
location Netherlands
age
visits member for 2 years, 7 months
seen 9 hours ago

Hacker, programmer, reverse engineer. Currently mostly programming in c++, python and perl, using boost + STL c++ libraries a lot. Enjoy reverse engineering, and patching basebands. Wrote tools for hacking on windows mobile devices, unpackers for many rom filesystems. Fast searching tools for bitcoin blockchain. Often using IDA to investigate binaries.


Oct
9
comment How costly is to find millions of large prime numbers for RSA?
I suggest you calculate a sha256 of you set value, and then using miller-rabin + increment, find the first prime following that hash value.
Oct
1
awarded  Teacher
Oct
1
answered EC Public Key length in ASN.1 DER
Sep
26
comment EC Public Key length in ASN.1 DER
the last 2 numbers are the ecdsa signature, it is two unsigned integers, when the highest byte happens to be larger than 127, the asn.1 BER encoding adds an extra zero.
Sep
24
awarded  Autobiographer
Sep
11
comment How can I know when a file was signed?
You could add a sequence number to the authenticatedAttributes field of the signature, and make sure that each sequence number + signaturehash has been published or registered with a trusted party. That way it would be hard for anyone ( including you ) to claim that a given sequence number belongs to a different signature.
Aug
13
awarded  Enthusiast
Aug
10
comment What does well-typed mean?
see Intuitionistic type theory or Simply typed lambda calculus
Aug
3
comment Point addition equation in projective co ordinates
I found this, a database of curve equations, with all possible addition formulas. not your curve though.
Jul
20
comment Can a EC private key be derived from a public key?
d+q for 0<d<2^n-q gives the same pubkey as d.
Jul
18
awarded  Editor
Jul
18
revised How to calculate complexity of ElGamal cryptosystem?
improved layout of code sample
Jul
18
suggested suggested edit on How to calculate complexity of ElGamal cryptosystem?
Jul
15
comment Why use $(r,s)$ instead of $(r,s^{-1})$ as DSA signature?
The signature verification involves two elliptic curve multiplications, which take way more time than the modular division, so there is not really a point to precalculate this.
Jul
15
awarded  Supporter
Mar
20
comment Order Preserving Encryption for Numeric Data Values
If the list of messages is static, you could of course just prepend the indexnumber of the message to the encrypted message.
Mar
20
comment Order Preserving Encryption for Numeric Data Values
you probably don't need the have the numerical encrypted values ordered, but it would suffice if you had some function f: f(E(m1), E(m2)) = m1<m2