The Amazing World Pad 2

Plots
World's simplest online string and text left padding tool. Just paste your text in the form below, press Left Pad button, and every line of your text gets left padded. Press button, left pad. No ads, nonsense or garbage.

Summary
Official messages often start and end in predictable ways: My dear ambassador, Weather report, Sincerely yours, etc. The primary use of padding with classical ciphers is to prevent the cryptanalyst from using that predictability to find known plaintext[1] that aids in breaking the encryption. Random length padding also prevents an attacker from knowing the exact length of the plaintext message.

Many classical ciphers arrange the plaintext into particular patterns (e.g., squares, rectangles, etc.) and if the plaintext doesn't 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 kinds of cryptanalysis more difficult.

A famous example of classical padding which caused a great misunderstanding is "the world wonders".

Hash functions
Most modern cryptographic hash functions 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 length extension attacks.

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 Merkle–Damgård construction.

Block cipher mode of operation
Electronic codebook and cipher-block chaining (CBC) mode are examples of block cipher mode of operation. Block cipher modes for symmetric-key encryption algorithms 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.

There is currently[when?] a shift to use streaming mode of operation instead of block mode of operation.[citation needed] An example of streaming mode encryption is the counter mode of operation [2]. 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 ciphertext stealing or residual block terminationavoid the need for padding.

A disadvantage of padding is that it makes the plain text of the message susceptible to padding oracle attacks. 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 message authentication code (MAC) or digital signature before removal of the padding bytes, or by switching to a streaming mode of operation.

Bit padding[edit]
Bit padding can be applied to messages of any size.

A single set ('1') bit is added to the message and then as many reset ('0') bits as required (possibly none) are added. The number of reset ('0') bits added will depend on the block boundary to which the message needs to be extended. In bit terms this is "1000 ... 0000".

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:

ISO 10126 (withdrawn, 2007[3][4]) 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.

Example: In the following example the block size is 8 bytes and padding is required for 4 bytes

Cast

 * Jacob Hopkins as Gumball Watterson
 * Young Maylay as Lawrence "Larry" Sherman/The Fishermen
 * Ishan Sharma as Tremple
 * Callahan Clark as Jeffrey Opptention
 * Trey Bumpass as James Rumpel
 * Kennedy Peil as Gumball Pieces
 * Diego Luna as Joyfully
 * Zoe Saldana as Elena History
 * Channing Tatum as Arthas Ultroning
 * Albert Brooks as Mister Opptents
 * Ellen DeGeneres as Miss Opptents
 * Dan Navarro as Let it Grow (singing voice)
 * Kwesi Boakye as Darwin Watterson
 * Kyla Rae Kowalewski as Anais Watterson
 * Teresa Gallagher as Nicole Watterson
 * Dan Russell as Richard Watterson
 * Bill Hunter as The Ultron Sherm