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Padding (cryptography)

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684:, but the padding will obscure only the least-significant bits of the object's total length, leaving the approximate length of large objects readily observable and hence still potentially uniquely identifiable by their length. If the maximum padding M is comparable to the size of the payload, in contrast, an eavesdropper's uncertainty about the message's true payload size is much larger, at the cost that padding may add up to 100% overhead ( 2614: 212: 722:
classes, then these plus-or-minus one payload lengths will consistently yield different padded lengths as well (plus-or-minus one block for example), leaking exactly the fine-grained information the attacker desires. Against such risks, randomized padding can offer more protection by independently obscuring the least-significant bits of message lengths.
729:, however, padding deterministically to a block size much smaller than the message payload obscures only the least-significant bits of the messages true length, leaving the messages's true approximate length largely unprotected. Padding messages to a power of two (or any other fixed base) reduces the maximum amount of 283:. Padding oracle attacks allow the attacker to gain knowledge of the plain text without attacking the block cipher primitive itself. Padding oracle attacks can be avoided by making sure that an attacker cannot gain knowledge about the removal of the padding bytes. This can be accomplished by verifying a 679:
A random number of additional padding bits or bytes may be appended to the end of a message, together with an indication at the end how much padding was added. If the amount of padding is chosen as a uniform random number between 0 and some maximum M, for example, then an eavesdropper will be unable
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The operation is referred to as "padding" because originally, random material was simply appended to the message to make it long enough for the primitive. This form of padding is not secure and is therefore no longer applied. A modern padding scheme aims to ensure that the attacker cannot manipulate
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streams that use variable bit rate encoding, the number of bits per unit of time is not obscured, and this can be exploited to guess spoken phrases. Similarly, the burst patterns that common video encoders produce are often sufficient to identify the streaming video a user is watching uniquely. Even
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Admiral Halsey interpreted the padding phrase "the world wonders" as a sarcastic reprimand, which caused him to have an emotional outburst and then lock himself in his bridge and sulk for an hour before he moved his forces to assist at the Battle off Samar. Halsey's radio operator should have been
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A deterministic padding scheme always pads a message payload of a given length to form an encrypted message of a particular corresponding output length. When many payload lengths map to the same padded output length, an eavesdropper cannot distinguish or learn any information about the payload's
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variations in payload size, such as plus or minus just one byte in a password-guessing attack for example. If the message sender is unlucky enough to send many messages whose payload lengths vary by only one byte, and that length is exactly on the border between two of the deterministic padding
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successive messages from the same sender, and those messages are similar in ways the attacker knows or can guess, then the eavesdropper can use statistical techniques to decrease and eventually even eliminate the benefit of randomized padding. For example, suppose a user's application regularly
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Many classical ciphers arrange the plaintext into particular patterns (e.g., squares, rectangles, etc.) and if the plaintext does not exactly fit, it is often necessary to supply additional letters to fill out the pattern. Using nonsense letters for this purpose has a side benefit of making some
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is any of a number of distinct practices which all include adding data to the beginning, middle, or end of a message prior to encryption. In classical cryptography, padding may include adding nonsense phrases to a message to obscure the fact that many messages end in predictable ways, e.g.
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is added. This is necessary so the deciphering algorithm can determine with certainty whether the last byte of the last block is a pad byte indicating the number of padding bytes added or part of the plaintext message. Consider a plaintext message that is an integer multiple of
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A single '1' bit is added to the message and then as many '0' bits as required (possibly none) are added. The number of '0' bits added will depend on the block boundary to which the message needs to be extended. In bit terms this is "1000 ... 0000".
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they talked. In some circumstances this leakage can be highly compromising. Consider for example when a military is organising a secret attack against another nation: it may suffice to alert the other nation for them to know merely that there
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plaintext byte, the deciphering algorithm can always treat the last byte as a pad byte and strip the appropriate number of pad bytes off the end of the ciphertext; said number of bytes to be stripped based on the value of the last byte.
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Many padding schemes are based on appending predictable data to the final block. For example, the pad could be derived from the total length of the message. This kind of padding scheme is commonly applied to hash algorithms that use the
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process messages in fixed-length blocks; all but the earliest hash functions include some sort of padding scheme. It is critical for cryptographic hash functions to employ termination schemes that prevent a hash from being vulnerable to
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Zero padding may not be reversible if the original file ends with one or more zero bytes, making it impossible to distinguish between plaintext data bytes and padding bytes. It may be used when the length of the message can be derived
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an endpoint to send messages regularly, such as if the victim is a public server. In such cases, the eavesdropper can simply compute the average over many observations to determine the length of the regular message's payload.
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harder by obscuring the true length of its payload. The choice of length to pad a message to may be made either deterministically or randomly; each approach has strengths and weaknesses that apply in different contexts.
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All the bytes that are required to be padded are padded with zero. The zero padding scheme has not been standardized for encryption, although it is specified for hashes and MACs as Padding Method 1 in ISO/IEC 10118-1 and
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This method can be used to pad messages which are any number of bits long, not necessarily a whole number of bytes long. For example, a message of 23 bits that is padded with 9 bits in order to fill a 32-bit block:
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In ANSI X9.23, between 1 and 8 bytes are always added as padding. The block is padded with random bytes (although many implementations use 00) and the last byte of the block is set to the number of bytes added.
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Zero padding is sometimes also referred to as "null padding" or "zero byte padding". Some implementations may add an additional block of zero bytes if the plaintext is already divisible by the block size.
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of an object alone, such as a website, file, software package download, or online video, can uniquely identify an object, if the attacker knows or can guess a known set the object comes from. The
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sends messages of the same length, and the eavesdropper knows or can guess fact based on fingerprinting the user's application for example. Alternatively, an active attacker might be able to
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PKCS#5 padding is identical to PKCS#7 padding, except that it has only been defined for block ciphers that use a 64-bit (8-byte) block size. In practice, the two can be used interchangeably.
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ISO 10126 (withdrawn, 2007) specifies that the padding should be done at the end of that last block with random bytes, and the padding boundary should be specified by the last byte.
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Common deterministic padding methods include padding to a constant block size and padding to the next-larger power of two. Like randomized padding with a small maximum amount 
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Wright, Charles V.; Ballard, Lucas; Coull, Scott E.; Monrose, Fabian; Masson, Gerald M. (1 December 2010). "Uncovering Spoken Phrases in Encrypted Voice over IP Conversations".
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bits of information via its length, like padding to a power of two, but incurs much less overhead of at most 12% for tiny messages and decreasing gradually with message size.
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to determine the message's length precisely within that range. If the maximum padding M is small compared to the message's total size, then this padding will not add much
755:. Padding to a power of two increases message size overhead by up to 100%, however, and padding to powers of larger integer bases increase maximum overhead further. 461:. With no additional information, the deciphering algorithm will not be able to determine whether the last byte is a plaintext byte or a pad byte. However, by adding 268:. Streaming modes of operation can encrypt and decrypt messages of any size and therefore do not require padding. More intricate ways of ending a message such as 2277: 1150:
Sun, Qixiang; Simon, D.R.; Wang, Yi-Min; Russell, W.; Padmanabhan, V.N.; Qiu, Lili (May 2002). "Statistical Identification of Encrypted Web Browsing Traffic".
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Even if perfect cryptographic routines are used, the attacker can gain knowledge of the amount of traffic that was generated. The attacker might not know what
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whose mantissa is no longer (i.e., contains no more significant bits) than its exponent. This length constraint ensures that a message leaks at most
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There is currently a shift to use streaming mode of operation instead of block mode of operation. An example of streaming mode encryption is the
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that "the world wonders" was padding; all other radio operators who received Admiral Nimitz's message correctly removed both padding phrases.
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that aids in breaking the encryption. Random length padding also prevents an attacker from knowing the exact length of the plaintext message.
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Halsey's radio operator mistook some of the padding for the message and so Admiral Halsey ended up reading the following message:
2176: 1286: 1121:. International Workshop on Privacy Enhancing Technologies. Lecture Notes in Computer Science. Vol. 2482. pp. 171–178. 2055: 265: 203:
require plain text input that is a multiple of the block size, so messages may have to be padded to bring them to this length.
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the plaintext to exploit the mathematical structure of the primitive and will usually be accompanied by a proof, often in the
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bytes. This means in practice that the first byte is a mandatory byte valued '80' (Hexadecimal) followed, if needed, by 0 to
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Information technology – Security techniques – Message Authentication Codes (MACs) – Part 1: Mechanisms using a block cipher
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Example: In the following example the block size is 8 bytes, and padding is required for 4 bytes (in hexadecimal format)
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GG FROM CINCPAC ACTION COM THIRD FLEET INFO COMINCH CTF SEVENTY-SEVEN X WHERE IS RPT WHERE IS TASK FORCE THIRTY FOUR RR
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are added. The number of bytes added will depend on the block boundary to which the message needs to be extended.
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Nikitin, Kirill; Barman, Ludovic; Lueks, Wouter; Underwood, Matthew; Hubaux, Jean-Pierre; Ford, Bryan (2019).
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Padding is in whole bytes. The value of each added byte is the number of bytes that are added, i.e.
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Example: In the following example, the block size is 8 bytes and padding is required for 4 bytes
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Example: In the following example the block size is 8 bytes and padding is required for 4 bytes
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Example: In the following example the block size is 8 bytes and padding is required for 4 bytes
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Example: In the following example the block size is 8 bytes and padding is required for 4 bytes
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A disadvantage of padding is that it makes the plain text of the message susceptible to
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In addition, in common scenarios in which an eavesdropper has the opportunity to see
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Byte padding can be applied to messages that can be encoded as an integral number of
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Summarizing Known Attacks on Transport Layer Security (TLS) and Datagram TLS (DTLS)
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This padding method (as well as the previous two) is well-defined if and only if
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removal of the padding bytes, or by switching to a streaming mode of operation.
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A famous example of classical padding which caused a great misunderstanding is "
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Information technology – Security techniques – Hash-functions – Part 1: General
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The maximum block size is 255, as it is the biggest number a byte can contain.
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csrc.nist.gov/groups/ST/toolkit/BCM/documents/workshop2/presentations/xcbc.pdf
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Hintz, Andrew (April 2002). "Fingerprinting Websites Using Traffic Analysis".
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Willmott, H. P. (19 August 2005). "The Great Day of Wrath: 25 October 1944".
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If the length of the original data is an integer multiple of the block size
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On the other hand, suppose an eavesdropper can benefit from learning about
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This padding is the first step of a two-step padding scheme used in many
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such as SHA-224, SHA-256, SHA-384, SHA-512, SHA-512/224, and SHA-512/256
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Beauty and the Burst: Remote Identification of Encrypted Video Streams
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is to prevent the cryptanalyst from using that predictability to find
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01 02 02 03 03 03 04 04 04 04 05 05 05 05 05 06 06 06 06 06 06 etc.
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Where is, repeat, where is Task Force Thirty Four? The world wonders
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This article is about cryptography. For other uses of the term, see
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America's Fighting Admirals: Winning the War at Sea in World War II
77:" incident, which nearly caused an Allied loss at the World War II 1920: 1879: 1829: 1809: 1794: 1583: 1563: 1483: 1448: 656: 652: 583: 181: 177: 1769: 1678: 1593: 1588: 1578: 1558: 1430: 1415: 762:, deterministically pads messages to lengths representable as a 639: 587: 400: 352: 2259: 1275: 1096:
Schuster, Roei; Shmatikov, Vitaly; Tromer, Eran (August 2017).
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of encrypted content length was used to extract passwords from
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Adding data to a message prior to encryption to hide its length
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Official messages often start and end in predictable ways:
1154:. IEEE Symposium on Security and Privacy. pp. 19–30. 199:. Some block cipher modes (CBC and PCBC essentially) for 1240:
Sheffer, Y.; Holz, R.; Saint-Andre, P. (February 2015).
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Proceedings 2002 IEEE Symposium on Security and Privacy
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Cryptographically secure pseudorandom number generator
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Proceedings on Privacy Enhancing Technologies (PoPETS)
515:... | DD DD DD DD DD DD DD DD | DD DD DD DD DD DD DD 232:. Please help to ensure that disputed statements are 1263: 943:
https://www.cs.columbia.edu/~smb/classes/s09/l05.pdf
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Bit padding can be applied to messages of any size.
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ACM Transactions on Information and System Security
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My dear ambassador, Weather report, Sincerely yours
896: 512:The next example shows a padding of just one byte 101:Where is, repeat, where is Task Force Thirty Four? 867:The Battle of Leyte Gulf: The Last Fleet Action 127: 111: 99: 733:that the message can leak via its length from 2271: 1287: 8: 848:The Hut Six Story: Breaking the Enigma Codes 538:... | DD DD DD DD DD DD DD DD | DD DD DD DD 505:... | DD DD DD DD DD DD DD DD | DD DD DD DD 457:bytes with the last byte of plaintext being 437:... | DD DD DD DD DD DD DD DD | DD DD DD DD 388:... | DD DD DD DD DD DD DD DD | DD DD DD DD 370:... | DD DD DD DD DD DD DD DD | DD DD DD DD 805:, which are sometimes confused with padding 622:were talking about, but can know that they 614:Traffic analysis and protection via padding 2278: 2264: 2256: 1294: 1280: 1272: 1268: 1264: 860: 858: 856: 448:, then an extra block of bytes with value 1216: 1206: 1181: 1179: 1064: 252:Learn how and when to remove this message 550:. It is often applied to binary encoded 228:Relevant discussion may be found on the 926:"FIPS 180-4 Secure Hash Standard (SHS)" 890: 888: 886: 836: 710:true length within one of these length 142:kinds of cryptanalysis more difficult. 93:in WWII, sent the following message to 62:, etc. The primary use of padding with 666:Padding an encrypted message can make 332:. In this context, it is specified by 91:Commander in Chief, U.S. Pacific Fleet 7: 827:, another technique to prevent cribs 760:padded uniform random blobs or PURBs 638:As another example, when encrypting 635:a lot of secret activity going on. 201:symmetric-key encryption algorithms 956:"ANSI X9.23 cipher block chaining" 339:This padding scheme is defined by 313:... | 1011 1001 1101 0100 0010 011 25: 655:communications in the well-known 285:message authentication code (MAC) 2613: 2612: 210: 758:The PADMÉ scheme, proposed for 562:can usually be stripped off as 2474:Information-theoretic security 1119:Privacy Enhancing Technologies 197:block cipher mode of operation 188:Block cipher mode of operation 1: 869:. Indiana University Press. 421:The padding will be one of: 276:avoid the need for padding. 195:(CBC) mode is an example of 157:cryptographic hash functions 2590:Message authentication code 2545:Cryptographic hash function 2358:Cryptographic hash function 1160:10.1109/SECPRI.2002.1004359 170:Merkle–Damgård construction 109:added, the message became: 2664: 2469:Harvest now, decrypt later 903:. MBI Publishing Company. 819:padded uniform random blob 274:residual block termination 134:tipped off by the letters 105:With padding (bolded) and 29: 2608: 2585:Post-quantum cryptography 2255: 2177:Time/memory/data tradeoff 1271: 1267: 1104:USENIX Security Symposium 688:blow-up) to the message. 266:counter mode of operation 2575:Quantum key distribution 2565:Authenticated encryption 2420:Random number generation 1965:Whitening transformation 1218:10.2478/popets-2019-0056 1127:10.1007/3-540-36467-6_13 162:length extension attacks 32:Padding (disambiguation) 2570:Public-key cryptography 2560:Symmetric-key algorithm 2363:Key derivation function 2323:Cryptographic primitive 2316:Authentication protocol 2306:Outline of cryptography 2301:History of cryptography 1936:Confusion and diffusion 1075:10.1145/1880022.1880029 895:Tuohy, William (2007). 580:public key cryptography 574:Public key cryptography 2311:Cryptographic protocol 787:Chaffing and winnowing 556:null-terminated string 281:padding oracle attacks 146:Symmetric cryptography 131: 123: 103: 87:Admiral Chester Nimitz 54:Classical cryptography 2464:End-to-end encryption 2410:Cryptojacking malware 2229:Initialization vector 1023:ISO/IEC 10118-1:2016 799:Initialization vector 764:floating point number 705:Deterministic padding 414:bytes, each of value 343:as Padding Method 2. 193:Cipher-block chaining 115:TURKEY TROTS TO WATER 81:, part of the larger 2580:Quantum cryptography 2504:Trusted timestamping 2008:3-subset MITM attack 1624:Intel Cascade Cipher 1604:Hasty Pudding cipher 1037:ISO/IEC 9797-1:2011 960:IBM Knowledge Center 465:bytes each of value 221:factual accuracy is 83:Battle of Leyte Gulf 2343:Cryptographic nonce 2047:Differential-linear 1011:ISO/IEC 7816-4:2005 803:salt (cryptography) 793:Ciphertext stealing 608:random oracle model 270:ciphertext stealing 95:Admiral Bull Halsey 85:. In that example, 2648:Padding algorithms 2449:Subliminal channel 2433:Pseudorandom noise 2380:Key (cryptography) 2120:Differential-fault 1338:internal mechanics 825:Russian copulation 675:Randomized padding 431:is less than 256. 2630: 2629: 2626: 2625: 2509:Key-based routing 2499:Trapdoor function 2370:Digital signature 2251: 2250: 2247: 2246: 2234:Mode of operation 1911:Lai–Massey scheme 1136:978-3-540-00565-0 809:Key encapsulation 396:PKCS#5 and PKCS#7 289:digital signature 262: 261: 254: 119:THE WORLD WONDERS 75:the world wonders 64:classical ciphers 16:(Redirected from 2655: 2616: 2615: 2444:Insecure channel 2280: 2273: 2266: 2257: 2105:Power-monitoring 1946:Avalanche effect 1654:Khufu and Khafre 1307:security summary 1296: 1289: 1282: 1273: 1269: 1265: 1246: 1245: 1237: 1231: 1230: 1220: 1210: 1192: 1183: 1174: 1173: 1147: 1141: 1140: 1114: 1108: 1107: 1093: 1087: 1086: 1068: 1048: 1042: 1034: 1028: 1020: 1014: 1006: 1000: 997:ISO 10126-2:1991 992: 986: 983:ISO 10126-1:1991 978: 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783: 767: 745: 734: 707: 685: 677: 616: 598:applied to the 576: 543: 525: 520: 510: 486: 468: 464: 456: 451: 447: 442: 430: 425: 417: 413: 398: 393: 380: 375: 361: 349: 318: 300: 258: 247: 241: 238: 227: 219:This section's 215: 211: 190: 153: 148: 113: 68:known plaintext 56: 48:sincerely yours 35: 28: 23: 22: 15: 12: 11: 5: 2661: 2659: 2651: 2650: 2645: 2635: 2634: 2628: 2627: 2624: 2623: 2621: 2620: 2609: 2606: 2605: 2603: 2602: 2597: 2595:Random numbers 2592: 2587: 2582: 2577: 2572: 2567: 2562: 2557: 2552: 2547: 2541: 2539: 2535: 2534: 2532: 2531: 2526: 2521: 2519:Garlic routing 2516: 2511: 2506: 2501: 2496: 2491: 2486: 2481: 2476: 2471: 2466: 2461: 2456: 2451: 2446: 2441: 2439:Secure channel 2436: 2430: 2429: 2428: 2417: 2412: 2407: 2402: 2400:Key stretching 2397: 2392: 2387: 2382: 2377: 2372: 2367: 2366: 2365: 2360: 2350: 2348:Cryptovirology 2345: 2340: 2335: 2333:Cryptocurrency 2330: 2325: 2320: 2319: 2318: 2308: 2303: 2297: 2295: 2291: 2290: 2285: 2283: 2282: 2275: 2268: 2260: 2253: 2252: 2249: 2248: 2245: 2244: 2242: 2241: 2236: 2231: 2225: 2223: 2219: 2218: 2216: 2215: 2210: 2205: 2200: 2195: 2189: 2187: 2183: 2182: 2180: 2179: 2174: 2169: 2164: 2159: 2154: 2149: 2144: 2139: 2134: 2129: 2124: 2123: 2122: 2117: 2112: 2107: 2102: 2092: 2087: 2082: 2077: 2069: 2064: 2059: 2052:Distinguishing 2049: 2044: 2043: 2042: 2037: 2032: 2022: 2012: 2011: 2010: 2005: 1995: 1984: 1982: 1972: 1971: 1969: 1968: 1958: 1953: 1948: 1943: 1938: 1933: 1928: 1923: 1918: 1916:Product cipher 1913: 1908: 1903: 1897: 1895: 1891: 1890: 1888: 1887: 1882: 1877: 1872: 1867: 1862: 1857: 1852: 1847: 1842: 1837: 1832: 1827: 1822: 1817: 1812: 1807: 1802: 1797: 1792: 1787: 1782: 1777: 1772: 1767: 1762: 1757: 1752: 1747: 1742: 1737: 1732: 1727: 1722: 1717: 1712: 1707: 1702: 1697: 1692: 1687: 1682: 1671: 1666: 1661: 1656: 1651: 1646: 1641: 1636: 1631: 1626: 1621: 1616: 1611: 1606: 1601: 1596: 1591: 1586: 1581: 1576: 1571: 1566: 1561: 1556: 1551: 1546: 1544:Cryptomeria/C2 1541: 1536: 1531: 1526: 1521: 1516: 1511: 1506: 1501: 1496: 1491: 1486: 1481: 1476: 1471: 1466: 1461: 1456: 1451: 1445: 1443: 1437: 1436: 1434: 1433: 1428: 1423: 1418: 1413: 1408: 1403: 1398: 1393: 1388: 1383: 1378: 1372: 1370: 1364: 1363: 1361: 1360: 1355: 1350: 1345: 1331: 1326: 1320: 1318: 1312: 1311: 1301: 1299: 1298: 1291: 1284: 1276: 1262: 1261: 1253: 1250: 1248: 1247: 1232: 1175: 1168: 1142: 1135: 1109: 1088: 1043: 1029: 1015: 1001: 987: 973: 947: 935: 916: 909: 882: 875: 852: 835: 833: 830: 829: 828: 822: 812: 806: 796: 790: 782: 779: 706: 703: 676: 673: 615: 612: 575: 572: 560:null character 537: 530:ISO/IEC 9797-1 524: 521: 514: 504: 485: 484:ISO/IEC 7816-4 482: 466: 462: 454: 449: 445: 436: 428: 423: 415: 411: 397: 394: 387: 379: 376: 369: 360: 357: 348: 345: 341:ISO/IEC 9797-1 322:hash functions 312: 299: 296: 260: 259: 218: 216: 209: 189: 186: 152: 151:Hash functions 149: 147: 144: 55: 52: 26: 24: 14: 13: 10: 9: 6: 4: 3: 2: 2660: 2649: 2646: 2644: 2641: 2640: 2638: 2619: 2611: 2610: 2607: 2601: 2600:Steganography 2598: 2596: 2593: 2591: 2588: 2586: 2583: 2581: 2578: 2576: 2573: 2571: 2568: 2566: 2563: 2561: 2558: 2556: 2555:Stream cipher 2553: 2551: 2548: 2546: 2543: 2542: 2540: 2536: 2530: 2527: 2525: 2522: 2520: 2517: 2515: 2514:Onion routing 2512: 2510: 2507: 2505: 2502: 2500: 2497: 2495: 2494:Shared secret 2492: 2490: 2487: 2485: 2482: 2480: 2477: 2475: 2472: 2470: 2467: 2465: 2462: 2460: 2457: 2455: 2452: 2450: 2447: 2445: 2442: 2440: 2437: 2434: 2431: 2426: 2423: 2422: 2421: 2418: 2416: 2413: 2411: 2408: 2406: 2403: 2401: 2398: 2396: 2393: 2391: 2390:Key generator 2388: 2386: 2383: 2381: 2378: 2376: 2373: 2371: 2368: 2364: 2361: 2359: 2356: 2355: 2354: 2353:Hash function 2351: 2349: 2346: 2344: 2341: 2339: 2336: 2334: 2331: 2329: 2328:Cryptanalysis 2326: 2324: 2321: 2317: 2314: 2313: 2312: 2309: 2307: 2304: 2302: 2299: 2298: 2296: 2292: 2288: 2281: 2276: 2274: 2269: 2267: 2262: 2261: 2258: 2254: 2240: 2237: 2235: 2232: 2230: 2227: 2226: 2224: 2220: 2214: 2211: 2209: 2206: 2204: 2201: 2199: 2196: 2194: 2191: 2190: 2188: 2184: 2178: 2175: 2173: 2170: 2168: 2165: 2163: 2160: 2158: 2155: 2153: 2150: 2148: 2145: 2143: 2140: 2138: 2135: 2133: 2132:Interpolation 2130: 2128: 2125: 2121: 2118: 2116: 2113: 2111: 2108: 2106: 2103: 2101: 2098: 2097: 2096: 2093: 2091: 2088: 2086: 2083: 2081: 2078: 2076: 2075: 2070: 2068: 2065: 2063: 2060: 2057: 2053: 2050: 2048: 2045: 2041: 2038: 2036: 2033: 2031: 2028: 2027: 2026: 2023: 2020: 2016: 2013: 2009: 2006: 2004: 2001: 2000: 1999: 1996: 1993: 1989: 1986: 1985: 1983: 1980: 1979:cryptanalysis 1973: 1966: 1962: 1961:Key whitening 1959: 1957: 1954: 1952: 1949: 1947: 1944: 1942: 1939: 1937: 1934: 1932: 1929: 1927: 1924: 1922: 1919: 1917: 1914: 1912: 1909: 1907: 1904: 1902: 1899: 1898: 1896: 1892: 1886: 1883: 1881: 1878: 1876: 1873: 1871: 1868: 1866: 1863: 1861: 1858: 1856: 1853: 1851: 1848: 1846: 1843: 1841: 1838: 1836: 1833: 1831: 1828: 1826: 1823: 1821: 1818: 1816: 1813: 1811: 1808: 1806: 1803: 1801: 1798: 1796: 1793: 1791: 1788: 1786: 1783: 1781: 1778: 1776: 1773: 1771: 1768: 1766: 1763: 1761: 1758: 1756: 1753: 1751: 1750:New Data Seal 1748: 1746: 1743: 1741: 1738: 1736: 1733: 1731: 1728: 1726: 1723: 1721: 1718: 1716: 1713: 1711: 1708: 1706: 1703: 1701: 1698: 1696: 1693: 1691: 1688: 1686: 1683: 1680: 1676: 1672: 1670: 1667: 1665: 1662: 1660: 1657: 1655: 1652: 1650: 1647: 1645: 1642: 1640: 1637: 1635: 1632: 1630: 1627: 1625: 1622: 1620: 1617: 1615: 1612: 1610: 1607: 1605: 1602: 1600: 1597: 1595: 1592: 1590: 1587: 1585: 1582: 1580: 1577: 1575: 1572: 1570: 1567: 1565: 1562: 1560: 1557: 1555: 1552: 1550: 1547: 1545: 1542: 1540: 1537: 1535: 1532: 1530: 1527: 1525: 1522: 1520: 1517: 1515: 1512: 1510: 1507: 1505: 1502: 1500: 1497: 1495: 1492: 1490: 1489:BEAR and LION 1487: 1485: 1482: 1480: 1477: 1475: 1472: 1470: 1467: 1465: 1462: 1460: 1457: 1455: 1452: 1450: 1447: 1446: 1444: 1438: 1432: 1429: 1427: 1424: 1422: 1419: 1417: 1414: 1412: 1409: 1407: 1404: 1402: 1399: 1397: 1394: 1392: 1389: 1387: 1384: 1382: 1379: 1377: 1374: 1373: 1371: 1365: 1359: 1356: 1354: 1351: 1349: 1346: 1343: 1339: 1335: 1332: 1330: 1327: 1325: 1322: 1321: 1319: 1313: 1308: 1304: 1303:Block ciphers 1297: 1292: 1290: 1285: 1283: 1278: 1277: 1274: 1270: 1266: 1260: 1256: 1255: 1251: 1243: 1236: 1233: 1228: 1224: 1219: 1214: 1209: 1204: 1200: 1196: 1189: 1182: 1180: 1176: 1171: 1169:0-7695-1543-6 1165: 1161: 1157: 1153: 1146: 1143: 1138: 1132: 1128: 1124: 1120: 1113: 1110: 1105: 1101: 1100: 1092: 1089: 1084: 1080: 1076: 1072: 1067: 1062: 1058: 1054: 1047: 1044: 1041: 1040: 1033: 1030: 1027: 1026: 1019: 1016: 1013: 1012: 1009:ISO catalog, 1005: 1002: 999: 998: 995:ISO catalog, 991: 988: 985: 984: 981:ISO catalog, 977: 974: 961: 957: 951: 948: 944: 939: 936: 927: 920: 917: 912: 910:9780760329856 906: 901: 900: 891: 889: 887: 883: 878: 876:9780253003515 872: 868: 861: 859: 857: 853: 849: 845: 840: 837: 831: 826: 823: 820: 816: 813: 810: 807: 804: 800: 797: 794: 791: 788: 785: 784: 780: 778: 774: 770: 765: 761: 756: 752: 748: 741: 737: 732: 728: 723: 720: 715: 713: 704: 702: 699: 694: 689: 683: 674: 672: 669: 664: 662: 658: 654: 650: 646: 641: 640:Voice Over IP 636: 634: 629: 625: 621: 620:Alice and Bob 613: 611: 609: 603: 601: 600:RSA algorithm 597: 593: 589: 585: 581: 573: 571: 567: 565: 561: 557: 553: 549: 541: 536: 533: 531: 522: 518: 513: 508: 503: 500: 498: 494: 490: 483: 481: 478: 475: 472: 460: 440: 435: 432: 422: 419: 408: 406: 402: 395: 391: 386: 383: 377: 373: 368: 365: 358: 356: 354: 346: 344: 342: 337: 335: 331: 327: 323: 316: 311: 307: 303: 297: 295: 293: 290: 286: 282: 277: 275: 271: 267: 256: 253: 245: 235: 231: 225: 224: 217: 208: 207: 204: 202: 198: 194: 187: 185: 183: 179: 175: 171: 165: 163: 158: 150: 145: 143: 139: 137: 130: 126: 122: 120: 116: 110: 108: 102: 98: 96: 92: 88: 84: 80: 76: 71: 69: 65: 61: 53: 51: 49: 44: 40: 33: 19: 2643:Cryptography 2550:Block cipher 2395:Key schedule 2385:Key exchange 2375:Kleptography 2338:Cryptosystem 2287:Cryptography 2238: 2137:Partitioning 2095:Side-channel 2073: 2040:Higher-order 2025:Differential 1906:Key schedule 1235: 1198: 1194: 1151: 1145: 1118: 1112: 1098: 1091: 1056: 1052: 1046: 1038: 1032: 1024: 1018: 1010: 1004: 996: 990: 982: 976: 964:. Retrieved 959: 950: 938: 919: 898: 866: 847: 839: 818: 772: 768: 757: 750: 746: 739: 735: 726: 724: 718: 716: 711: 708: 697: 692: 690: 678: 665: 649:side-channel 644: 637: 632: 627: 626:talking and 623: 617: 604: 577: 568: 544: 539: 534: 526: 523:Zero padding 516: 511: 506: 501: 496: 492: 489:ISO/IEC 7816 487: 479: 476: 470: 458: 443: 438: 433: 426: 420: 409: 399: 389: 384: 381: 371: 366: 362: 350: 347:Byte padding 338: 319: 314: 308: 304: 301: 291: 278: 263: 248: 242:January 2016 239: 220: 191: 182:SHA-2 family 166: 155:Most modern 154: 140: 135: 132: 128: 124: 118: 114: 112: 104: 100: 72: 59: 57: 47: 42: 39:cryptography 36: 2538:Mathematics 2529:Mix network 2222:Utilization 2208:NSA Suite B 2193:AES process 2142:Rubber-hose 2080:Related-key 1988:Brute-force 1367:Less common 1201:(4): 6–33. 966:31 December 731:information 548:out-of-band 540:00 00 00 00 507:80 00 00 00 439:04 04 04 04 390:81 A6 23 04 372:00 00 00 04 315:1 0000 0000 298:Bit padding 2637:Categories 2489:Ciphertext 2459:Decryption 2454:Encryption 2415:Ransomware 2172:Chi-square 2090:Rotational 2030:Impossible 1951:Block size 1845:Spectr-H64 1669:Ladder-DES 1664:Kuznyechik 1609:Hierocrypt 1479:BassOmatic 1442:algorithms 1369:algorithms 1342:Triple DES 1317:algorithms 1208:1806.03160 832:References 645:total size 564:whitespace 469:after the 359:ANSI X9.23 336:step 3.1. 324:including 2479:Plaintext 2147:Black-bag 2067:Boomerang 2056:Known-key 2035:Truncated 1860:Threefish 1855:SXAL/MBAL 1745:MultiSwap 1700:MacGuffin 1659:KN-Cipher 1599:Grand Cru 1554:CS-Cipher 1534:COCONUT98 1244:(Report). 1061:CiteSeerX 1059:(4): 35. 771:(log log 749:(log log 663:attacks. 558:) as the 378:ISO 10126 230:talk page 2618:Category 2524:Kademlia 2484:Codetext 2427:(CSPRNG) 2198:CRYPTREC 2162:Weak key 2115:Acoustic 1956:Key size 1800:Red Pike 1619:IDEA NXT 1499:Chiasmus 1494:CAST-256 1474:BaseKing 1459:Akelarre 1454:Adiantum 1421:Skipjack 1386:CAST-128 1381:Camellia 1329:Blowfish 1227:47011059 850:, p. 78. 781:See also 682:overhead 628:how much 405:RFC 5652 223:disputed 172:such as 107:metadata 2294:General 2239:Padding 2157:Rebound 1865:Treyfer 1815:SAVILLE 1775:PRESENT 1765:NOEKEON 1710:MAGENTA 1705:Madryga 1685:Lucifer 1549:CRYPTON 1358:Twofish 1348:Serpent 1083:9622722 945:, pg 17 931:. NIST. 712:buckets 552:strings 334:RFC1321 43:padding 2405:Keygen 2203:NESSIE 2152:Davies 2100:Timing 2015:Linear 1975:Attack 1894:Design 1885:Zodiac 1850:Square 1825:SHACAL 1820:SC2000 1780:Prince 1760:Nimbus 1755:NewDES 1740:MULTI2 1730:MISTY1 1673:LOKI ( 1649:KHAZAD 1644:KeeLoq 1639:KASUMI 1634:Kalyna 1519:CLEFIA 1504:CIKS-1 1464:Anubis 1315:Common 1257:XCBC: 1225:  1166:  1133:  1081:  1063:  924:NIST. 907:  873:  698:induce 661:BREACH 586:v2.2, 584:PKCS#1 401:PKCS#7 292:before 180:, and 89:, the 2435:(PRN) 2085:Slide 1941:Round 1926:P-box 1921:S-box 1880:XXTEA 1840:Speck 1835:Simon 1830:SHARK 1810:SAFER 1795:REDOC 1720:Mercy 1679:89/91 1629:Iraqi 1594:G-DES 1584:FEA-M 1564:DES-X 1529:Cobra 1484:BATON 1469:Ascon 1449:3-Way 1440:Other 1223:S2CID 1203:arXiv 1191:(PDF) 1079:S2CID 962:. IBM 929:(PDF) 738:(log 719:small 657:CRIME 653:HTTPS 353:bytes 178:SHA-1 2213:CNSA 2072:Mod 1998:MITM 1770:NUSH 1725:MESH 1715:MARS 1589:FROG 1579:FEAL 1559:DEAL 1539:Crab 1524:CMEA 1431:XTEA 1416:SEED 1396:IDEA 1391:GOST 1376:ARIA 1199:2019 1164:ISBN 1131:ISBN 968:2018 905:ISBN 871:ISBN 815:PURB 693:many 659:and 643:the 624:were 596:OAEP 588:OAEP 328:and 174:MD-5 2167:Tau 2127:XSL 1931:SPN 1875:xmx 1870:UES 1805:S-1 1790:RC2 1735:MMB 1614:ICE 1569:DFC 1426:TEA 1411:RC6 1406:RC5 1401:LEA 1353:SM4 1334:DES 1324:AES 1213:doi 1156:doi 1123:doi 1071:doi 817:or 744:to 592:PSS 578:In 330:SHA 326:MD5 287:or 272:or 37:In 2639:: 1695:M8 1690:M6 1677:, 1675:97 1574:E2 1340:, 1221:. 1211:. 1197:. 1193:. 1178:^ 1162:. 1129:. 1102:. 1077:. 1069:. 1057:13 1055:. 958:. 885:^ 855:^ 846:, 801:, 686:2× 633:is 590:, 566:. 542:| 532:. 519:| 517:80 509:| 471:01 459:01 441:| 407:. 392:| 374:| 355:. 317:| 176:, 164:. 136:RR 50:. 41:, 2279:e 2272:t 2265:v 2074:n 2058:) 2054:( 2021:) 2017:( 1994:) 1990:( 1981:) 1977:( 1967:) 1963:( 1785:Q 1681:) 1344:) 1336:( 1309:) 1305:( 1295:e 1288:t 1281:v 1229:. 1215:: 1205:: 1172:. 1158:: 1139:. 1125:: 1106:. 1085:. 1073:: 970:. 933:. 913:. 879:. 775:) 773:M 769:O 753:) 751:M 747:O 742:) 740:M 736:O 727:M 554:( 497:N 493:N 467:B 463:B 455:B 450:B 446:B 429:N 416:N 412:N 255:) 249:( 244:) 240:( 236:. 226:. 34:. 20:)

Index

Security padding
Padding (disambiguation)
cryptography
classical ciphers
known plaintext
the world wonders
Battle off Samar
Battle of Leyte Gulf
Admiral Chester Nimitz
Commander in Chief, U.S. Pacific Fleet
Admiral Bull Halsey
metadata
cryptographic hash functions
length extension attacks
Merkle–Damgård construction
MD-5
SHA-1
SHA-2 family
Cipher-block chaining
block cipher mode of operation
symmetric-key encryption algorithms
disputed
talk page
reliably sourced
Learn how and when to remove this message
counter mode of operation
ciphertext stealing
residual block termination
padding oracle attacks
message authentication code (MAC)

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