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LLegoLLaS

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Posts posted by LLegoLLaS

  1. Cisco Open Sources Experimental Small Domain Block Cipher

    in Stiri securitate

    Posted · Edited by LLegoLLaS

    In cryptography, Block ciphers such as AES or DES are a symmetric key cipher operating on fixed-length groups of bits, called blocks, and typically operate on large input data blocks i.e. 64 or more than 128, 256 bits.

    Block cipher encrypts Plain-text to Cipher-text by applying cryptographic key and algorithm to a block of data at once as a group rather than to one bit at a time, so that identical blocks of text do not get encrypted the same way.

    However, some applications need smaller blocks, and possibly non-binary blocks. So, to fulfil this need Cisco is providing a small block cipher , what it calls “FNR” (Flexible Naor and Reingold), but currently it is an experimental block cipher rather a production software.

    Sashank Dara, software engineer at the security technology group Cisco, says in a detailed explanation that FNR is a flexible length small domain block cipher for encrypting objects that works without the need for padding, as happens in the traditional block ciphers such as AES (Advanced Encryption Standard) and DES (Data Encryption Standard).

    “

    But one of the issues is the need for padding—so if you need to encrypt small amounts of data you may end with a huge difference in input vs. output size. As an example, using AES/128 on ECB mode to encrypt an IPv4 address results in an input size of 32 bits, but an output size of 128 bits. This may not be desired for some applications
    .” Sashank Dara said.

    FEATURES OF FNR

    Format-preserving encryption (FPE) - the length of plaintext and ciphertext remains same.

    FNR is flexible for large input domains that are greater than 32 bits and less than 128 bits.

    The encryption key length is not dependent on the input length and rather depends on underlying pseudo-random function (PRF).

    I have taken an example from Wikipedia to explain the importance of Format-preserving encryption (FPE):

    Suppose we want to encrypt a 16-digit credit card number 1234567812345670 using AES algorithm like ECB or CBC that will transform a credit card number into a large, fixed-length, binary value i.e. hexadecimal output value - 0x96a45cbcf9c2a9425cde9e274948cb67, which contains many bytes that are considered invalid when compared to a typical credit card number. If a credit card number is stored in a column of a database whose entries are char or varchar data, then the encrypted data cannot be stored in same column without changing the format of the column. If the encrypted data is Base64 encoded to ensure that it only contains valid characters, the size of the encrypted credit card number increases from 16 bytes to 24 bytes, changing the encrypted credit card number to lqRcvPnCqUJc3p4nSUjLZw==. In either case, applications that process the credit number may similarly be unable to handle an encrypted value without some modification.

    SMALL-BLOCK ENCRYPTION SECURITY?

    Small domain block ciphers are useful tool in designing privacy of sensitive data fields of smaller length, but smaller blocks leads to important security issues and building a secure small block cipher is known to be a tricky task.

    According to Cisco, FNR is an experimental small domain block cipher for encrypting objects like IPv4, Port numbers, MAC Addresses, IPv6 address and any random short strings and numbers, while preserving their input length.

    “Like all deterministic encryption methods, this does not provide semantic security, but determinism is needed in situations where anonymizing telemetry and log data (especially in cloud based network monitoring scenarios) is necessary,” Cisco warned.

    Cisco has Open Sourced the FNR encryption scheme under open source license LGPLv2 on Github.

    sursa:TheHackerNews

  6. Ce sistem de operare folosiți?

    in Cosul de gunoi

    Posted · Edited by LLegoLLaS

    Mai bine vezi din ce cauza ai disk usage ...vezi ce procese folossc hddul aiurea.

    Btw...poll-ul ar trebui facut cu multi-select.Multi folosim cel putin 2 sisteme de operare

    Folosesc Win8.1x64 + Ubuntu 14.04 si m-ar tenta un hackintosh

    Mobil: Android 4.4.2 (root+mods+custom recovery)

  15. Hackerul Guccifer, condamnat la şapte ani de închisoare cu executare

    in Stiri securitate

    Posted

    daca e sa comparam cu pedepsele luate de berbecali,borcea si ceilalti care au fraudat de milioane de euro...a luat exagerat de mult.Ce a facut e clar o nebunie dar ''cine-i prost,sa moara" .majoritatea probabil au fost "sparte" prin social engineering.Bravo lui ca a putut face asta dar multa muie pentru ca le-a facut publice imediat, iar nu dupa ce era sigur ca e in siguranta si nu i se putea lua urma.In fond nu cred ca a publicat ceva util (vezi wikileaks)

    //coherence not found today

  21. Cateva Free Trial VPS

    in Tutoriale in romana

    Posted · Edited by LLegoLLaS

    Host 1 Free

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    Ram: 128 MB

    Ram Burst: 640 MB

    Lasts for: FOREVER.

    Free-Trial-RegistrationCloud Share

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    Lasts for: 14 Days

    VPS.me

    Space: 5Gb

    Ram: 384 Mb

    Burst: ????

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    Atum Hosting

    Package 1

    Space: 25Gb

    Ram: 512mb

    Burst: ????

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    Package 2

    Space: 50Gb

    RAM: 1Gb

    Burst: ???

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    Package 3

    Space: 50Gb

    RAM: 2Gb

    Burst: ???

    Lasts for: 15 DAYS

    Elastic Host

    Space: 20GB

    RAM: 1GB

    Burst: ???

    Lasts for: 5 DAYS

    Microsoft Windows Azure

    Space: 35GB

    RAM: 128MB

    Burst: 128MB

    Lasts for: 90 DAYS

    Amazon Web Services

    Space: 5GB

    RAM: 613MB

    Burst: 613MB

    Lasts for: 1 YEAR

    AWS Free Usage Tier

    NephoScale Cloud Computing

    Space: 10GB

    RAM: 256MB

    Burst: 256MB

    Lasts for: 1 YEAR

    KVM Vserver (thanks Twiff)

    Space: upto 250 GB

    RAM: upto 4 GB

    Lasts for: 12 hours

    !!! Romania e restrictionata pe multe din ele deci folositi prezervativ la inregistrare

    Thanks to...someone...

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