Skip to content
By using Twitter’s services you agree to our Cookies Use. We and our partners operate globally and use cookies, including for analytics, personalisation, and ads.
  • Home Home Home, current page.
  • Moments Moments Moments, current page.

Saved searches

  • Remove
  • In this conversation
    Verified accountProtected Tweets @
Suggested users
  • Verified accountProtected Tweets @
  • Verified accountProtected Tweets @
  • Language: English
    • Bahasa Indonesia
    • Bahasa Melayu
    • Català
    • Čeština
    • Dansk
    • Deutsch
    • English UK
    • Español
    • Filipino
    • Français
    • Hrvatski
    • Italiano
    • Magyar
    • Nederlands
    • Norsk
    • Polski
    • Português
    • Română
    • Slovenčina
    • Suomi
    • Svenska
    • Tiếng Việt
    • Türkçe
    • Ελληνικά
    • Български език
    • Русский
    • Српски
    • Українська мова
    • עִבְרִית
    • العربية
    • فارسی
    • मराठी
    • हिन्दी
    • বাংলা
    • ગુજરાતી
    • தமிழ்
    • ಕನ್ನಡ
    • ภาษาไทย
    • 한국어
    • 日本語
    • 简体中文
    • 繁體中文
  • Have an account? Log in
    Have an account?
    · Forgot password?

    New to Twitter?
    Sign up
bascule's profile
Tony Arcieri
Tony Arcieri
Tony Arcieri
@bascule

Tweets

Tony Arcieri

@bascule

Co-founder @iqlusioninc, formerly @square @chain. Cryptography dilettante, polyglot programmer, key management wrangler, and infrastructure security specialist

San Francisco, CA
tonyarcieri.com
Joined May 2007

Tweets

  • © 2018 Twitter
  • About
  • Help Center
  • Terms
  • Privacy policy
  • Cookies
  • Ads info
Dismiss
Previous
Next

Go to a person's profile

Saved searches

  • Remove
  • In this conversation
    Verified accountProtected Tweets @
Suggested users
  • Verified accountProtected Tweets @
  • Verified accountProtected Tweets @

Promote this Tweet

Block

  • Tweet with a location

    You can add location information to your Tweets, such as your city or precise location, from the web and via third-party applications. You always have the option to delete your Tweet location history. Learn more

    Your lists

    Create a new list


    Under 100 characters, optional

    Privacy

    Copy link to Tweet

    Embed this Tweet

    Embed this Video

    Add this Tweet to your website by copying the code below. Learn more

    Add this video to your website by copying the code below. Learn more

    Hmm, there was a problem reaching the server.

    By embedding Twitter content in your website or app, you are agreeing to the Twitter Developer Agreement and Developer Policy.

    Preview

    Why you're seeing this ad

    Log in to Twitter

    · Forgot password?
    Don't have an account? Sign up »

    Sign up for Twitter

    Not on Twitter? Sign up, tune into the things you care about, and get updates as they happen.

    Sign up
    Have an account? Log in »

    Two-way (sending and receiving) short codes:

    Country Code For customers of
    United States 40404 (any)
    Canada 21212 (any)
    United Kingdom 86444 Vodafone, Orange, 3, O2
    Brazil 40404 Nextel, TIM
    Haiti 40404 Digicel, Voila
    Ireland 51210 Vodafone, O2
    India 53000 Bharti Airtel, Videocon, Reliance
    Indonesia 89887 AXIS, 3, Telkomsel, Indosat, XL Axiata
    Italy 4880804 Wind
    3424486444 Vodafone
    » See SMS short codes for other countries

    Confirmation

     

    Welcome home!

    This timeline is where you’ll spend most of your time, getting instant updates about what matters to you.

    Tweets not working for you?

    Hover over the profile pic and click the Following button to unfollow any account.

    Say a lot with a little

    When you see a Tweet you love, tap the heart — it lets the person who wrote it know you shared the love.

    Spread the word

    The fastest way to share someone else’s Tweet with your followers is with a Retweet. Tap the icon to send it instantly.

    Join the conversation

    Add your thoughts about any Tweet with a Reply. Find a topic you’re passionate about, and jump right in.

    Learn the latest

    Get instant insight into what people are talking about now.

    Get more of what you love

    Follow more accounts to get instant updates about topics you care about.

    Find what's happening

    See the latest conversations about any topic instantly.

    Never miss a Moment

    Catch up instantly on the best stories happening as they unfold.

    1. Thomas H. Ptacek‏ @tqbf 10 Apr 2013
      Replying to @tqbf

      @tqbf @bascule @matthew_d_green @dchest @marshray I don’t think getting CTR right is hard, but I don’t know what I don’t know.

      1 reply 0 retweets 0 likes
    2. Tony Arcieri‏ @bascule 10 Apr 2013
      Replying to @tqbf

      @tqbf @dchest @marshray that's why I was asking @matthew_d_green ;)

      3 replies 0 retweets 0 likes
    3. Matthew Green‏ @matthew_d_green 10 Apr 2013
      Replying to @bascule

      @bascule @tqbf @dchest @marshray But for god's sake please MAC that nonce ;)

      3 replies 0 retweets 0 likes
    4. Tony Arcieri‏ @bascule 10 Apr 2013
      Replying to @matthew_d_green

      @matthew_d_green @tqbf @dchest @marshray am I good to go with HMAC(nonce || ciphertext, hmac_key) ?

      2 replies 0 retweets 0 likes
    5. Marsh Ray‏ @marshray 10 Apr 2013
      Replying to @bascule

      @bascule @matthew_d_green @tqbf @dchest Usually key is first and include the nonce length. HMAC(K_mac, nonce_length || nonce || ciphertext)

      2 replies 0 retweets 0 likes
    6. Tony Arcieri‏ @bascule 10 Apr 2013
      Replying to @marshray

      @marshray @matthew_d_green @tqbf @dchest cool, thanks

      1 reply 0 retweets 0 likes
    7. Marsh Ray‏ @marshray 10 Apr 2013
      Replying to @bascule

      @bascule @matthew_d_green @tqbf @dchest But it's still busted until you ensure the pair (k, nonce) going into AES-CTR is globally unique

      3 replies 0 retweets 0 likes
    8. Tony Arcieri‏ @bascule 16 Apr 2013
      Replying to @marshray

      @marshray @matthew_d_green @tqbf @dchest sorry to dig this up again, but isn't solved by deriving a unique AES-CTR key and nonce via HKDF?

      1 reply 0 retweets 0 likes
    9. Marsh Ray‏ @marshray 16 Apr 2013
      Replying to @bascule

      @bascule @matthew_d_green @tqbf @dchest Not if you feed the nonce into the HKDF and leave it out of the AES-CTR initialization.

      2 replies 0 retweets 0 likes
    10. Marsh Ray‏ @marshray 16 Apr 2013
      Replying to @marshray

      @bascule You'd said something about starting the PT CTR at 0x00 (16 bytes). That leaves just the 128-bit key, too short to resist collisions

      1 reply 0 retweets 0 likes
      Tony Arcieri‏ @bascule 16 Apr 2013
      Replying to @marshray

      @marshray yeah, bad idea, I need to update the description to note I'm deriving an AES-CTR nonce too

      3:53 PM - 16 Apr 2013
      1 reply 0 retweets 0 likes
        1. New conversation
        2. Marsh Ray‏ @marshray 16 Apr 2013
          Replying to @bascule

          @bascule http://csrc.nist.gov/publications/nistpubs/800-38a/sp800-38a.pdf … "for each message encrypted by a key...must ensure uniqueness of all the counter blocks across all messages"

          2 replies 0 retweets 0 likes
        3. Tony Arcieri‏ @bascule 16 Apr 2013
          Replying to @marshray

          @marshray NaCl's aes128ctr uses a 128-bit nonce. Combined with a 128-bit key, isn't that sufficient? https://github.com/jedisct1/libsodium/blob/master/src/libsodium/include/sodium/crypto_stream_aes128ctr.h#L5 …

          1 reply 0 retweets 0 likes
        4. Marsh Ray‏ @marshray 16 Apr 2013
          Replying to @bascule

          @bascule Sufficient or no it's not CTR mode, which requires nonce and counter 2b separate bitfields and *no* wrapping or overlaps (ever)</b>

          1 reply 0 retweets 0 likes
        5. Tony Arcieri‏ @bascule 16 Apr 2013
          Replying to @marshray

          @marshray do you think there's a non-negligible chance of that happening given a 128-bit key and 128-bit nonce?

          1 reply 0 retweets 0 likes
        6. Marsh Ray‏ @marshray 16 Apr 2013
          Replying to @bascule

          @bascule despite what crypto_stream_aes128ctr.h implies, AES can't take a 128-bit nonce and still have room for a meaningful counter value

          2 replies 0 retweets 0 likes
        7. Tony Arcieri‏ @bascule 16 Apr 2013
          Replying to @marshray

          @marshray I am glad I am doing this as a thought exercise and not something anyone ever intends to use ;)

          0 replies 0 retweets 1 like
        8. End of conversation

      Loading seems to be taking a while.

      Twitter may be over capacity or experiencing a momentary hiccup. Try again or visit Twitter Status for more information.

        Promoted Tweet

        false

        • © 2018 Twitter
        • About
        • Help Center
        • Terms
        • Privacy policy
        • Cookies
        • Ads info