search for: cryptology

...: Ssh has a key agent allowing authentication to remote hosts without entering your password/passphrase again and again, which is very convenient. I think the 'su', 'sudo', and similiar commands could benefit from this idea and mechanism. I don't have the necessary expertise in cryptology to do this myself so I just want to throw this into the diskussion. If programs like 'su' und 'sudo' could be extended to use the ssh-agent a 'su-authorized-keys' file in the homedir of root would be enough to become root or any other user with any key in that file. For ...

has anyone noticed a performance gain with protocol 2? -David Higdon

Hi, There has been some recent work to improve the speed of the Message Authentication Codes (MACs) that are used in OpenSSH. The first improvement is a change from Markus Friedl to reuse the MAC context, rather than reinitialising it for every packet. This saves two calls to the underlying hash function (e.g. SHA1) for each packet. My tests found that this yielded at 12-16% speedup for bulk

...icrosoft's compiler has an explicit intrinsic in the form of _rotl8 and _rotl16 (IIRC -- this is from memory!). It would be nice to have a __builtin_rotl family in clang, in my opinion, but it would need back-end support from llvm. I would expect it to find use in code relating to hashing and cryptology. I know that the compiler *should* optimise uint32_t ror(uint32_t input, size_t rot_bits) { return (input >> rot_bits) | (input << ((sizeof(input) << 3) - rot_bits)); } and such macros / inline functions are common, but an intrinsic specifies intent better and could provide f...

...thing akin to openvpn's --tls-auth option, for all the reason's listed here: https://community.openvpn.net/openvpn/wiki/Hardening I have read http://www.tinc-vpn.org/documentation-1.1/tinc.pdf, but I have not seen anything similar. Or do I not need that feature at all because tinc handles cryptology different than openvpn ( tinc's uses RSA keys which are generated during setup currently - openvpn uses a cert authority with X.509 with different tls ciphers afaik )? While my understanding of crypto is not bad, I would not want to assume to judge crypto implementations on their design, so I...

...hing that slows down the attack is even more useful. I actually have training as a locksmith, with a specialty in masterkeying systems like rotating-constant and some obscure variations of RCM (this is one of the two masterkey systems explored in the infamous (in locksmith circles) paper "Cryptology and Physical Security: Rights Amplification in Master-Keyed Mechanical Locks" by Matt Blaze [1] [2]). In physical security all security is, in reality, through obscurity [3] (page 2, first paragraph): things like keeping the drill points secret (example: in a pin-tumbler lock, if you can...

*NOTE* IIRC compiling this with -O0 on x86-64 can yield the wrong result since clang will emit shifts and on intel shifts are mod the register size: ===== .section __TEXT,__text,regular,pure_instructions .globl _ror .align 4, 0x90 _ror: ## @ror .cfi_startproc ## BB#0: pushq %rbp Ltmp2: .cfi_def_cfa_offset 16 Ltmp3: .cfi_offset %rbp, -16 movq %rsp, %rbp

Pete Biggs wrote: > On Mon, 2017-11-27 at 12:10 -0500, Jerry Geis wrote: >> hi All, >> >> I happened to login to one of my servers today and saw 96000 failed >> login attempts. shown below is the address its coming from. I added it to my >> firewall to drop. >> >> Failed password for root from 123.183.209.135 port 14299 ssh2 >> >> FYI -

...he topics: Electronic System Integration (SoC, MPSoC, Mixed-Signal) Electronic Integration RF and Wireless Circuits and Systems Circuits and Systems for Communications Advanced Technologies (Nano, MEMS) Image and Video Image and video Processing Technology Compression, Coding, and Implementation Cryptology and Watermarking Storage, Retrieval, and Authentication Multimedia Management and diffusion of Multimedia Applications Multimedia Data Base Documents Modelisation and Interpretation Telecommunication?s Computer Science Telecommunications and Networks Networks Protocols and Wireless Networks Next...

Nice! Clever compiler.. On 07/28/2012 08:55 PM, Michael Gottesman wrote: > I can get clang/llvm to emit a rotate instruction on x86-64 when compiling C by just using -Os and the rotate from Hacker's Delight i.e., > > ====== > #include<stdlib.h> > #include<stdint.h> > > uint32_t ror(uint32_t input, size_t rot_bits) > { > return (input>>

Hi, Does FASTIPSec in FreeBSD use OCF framework ? Where can I find more documentation ? I wish to run cryptographic algorithms after setting a VPN. What command should I use to run a particular crytographic algorithm (e.g. 3DES etc.) Where can I find all such information ? -- Regards, Bubble

...ork positioning clearly compared to what exists. Here a non exhaustive list of the topics: Electronic Systems on chip Electronic integration Radiofrequence circuits and systems Telecommunications? circuits and systems Image and Video Image compression and coding Image processing technology Cryptology and watermarking Image 3D Multimedia Management and diffusion of multimedia applications Multimedia data base Documents modelisation and interpretation Telecommunication?s computer science Telecommunications and Networks Telecommunications Networks Communication protocoles Transmission...

...n algorithm and then try to keep it secret. A bad encryption algorithm, in this context, is an algorithm that can be broken by a sophisticated attacker even without knowledge about the algorithm itself. As you see, the reasons are of a practical nature, and are not derived from any fundamentals in cryptology. If we could find a practical way to keep secret both the key (that is the data the encryption method operates on) and also the method itself (or at least part of the method), then security would be greatly enhanced because the attacker would have less knowledge to work with. I believe there are s...

...slows down the attack is even more useful. > > I actually have training as a locksmith, with a specialty in > masterkeying systems like rotating-constant and some obscure variations of RCM (this is one of the two masterkey systems explored in the infamous (in locksmith circles) paper "Cryptology and Physical Security: Rights Amplification in Master-Keyed Mechanical Locks" by Matt Blaze [1] [2]). > > In physical security all security is, in reality, through obscurity [3] (page 2, first paragraph): things like keeping the drill points secret (example: in a pin-tumbler lock, if you...

At 01:59 PM 6/29/98 +0000, Kokoro Security Administrator wrote: >Hello everyone - > >I am looking for the name of a piece of hardware, and don''t know what it >is called. I am told that there exists such a thing (a switch? a router? >a special hub?) that will only send me traffic that is destined for me. simple definitions: --router: looks at a layer 3 address (such as