In CBC mode, you encrypt a block of data by taking the current plaintext block and exclusive-oring that wth the previous ciphertext block (or IV), and then sending the result of that through the block cipher; the output of the block cipher is the ciphertext block. GCM mode provides both privacy (encryption) and integrity.

2019年5月13日 · Simply put, after four new CBC-exclusive attacks have been revealed, all padding oracle attacks, they want to discourage it, as per a comment from the author of the update blogpost: We are only encouraging to move away from CBC based cipher suits after 4 new CBC based vulnerabilities.

2009年8月3日 · CCM is a simple combination of CTR mode and a CBC-MAC. Using two block cipher encryptions per block it is very slow. OCB is faster but encumbered by patents. For free (as in freedom) or non-military software the patent holder has granted a free license, though.

2017年8月1日 · You can use !SHA1:!SHA256:!SHA384 to disable all CBC mode ciphers. There are some non-CBC false positives that will also be disabled (RC4, NULL), but you probably also want to disable them anyway.

2017年4月17日 · $\begingroup$ Nitpick: CBC suites in SSL and TLS1.0 use the last block of the previous record as IV (except for first record, which uses the PRF expansion); that can be 64 or 128 bits depending on (the data-cipher component of) the negotiated suite. $\endgroup$

2018年9月20日 · It is similar to using the same IV for CBC mode, but for each and every block. Block ciphers in ECB mode are not CPA secure. Note that the newer TLS 1.3 protocol disallows CBC mode altogether. There have been many issues with the authenticate-then-encrypt and CBC mode in TLS, requiring protocol specific alterations to CBC padding mode for instance.

2021年3月5日 · CBC only provides semantic security if the IV is fully unpredictable to an adversary, i.e. all bits in the IV must appear random to an adversary. This means that the IV must be randomized which can be accomplished by the random IV, or by e.g. encrypting a nonce and using that as an IV.

2016年1月19日 · The AES_CBC mode uses AES in Cipher Block Chaining (CBC) mode. The AES_CTR mode uses AES in two slightly different modes in different contexts. When encrypting table space pages (such as pages in InnoDB, XtraDB, and …

2018年9月19日 · In CBC encryption, each ciphertext block is calculated based on the corresponding plaintext block and the previous ciphertext block (or the IV, for the first block). This means that if some plaintext block is changed, that change will (naturally enough) cause the corresponding ciphertext block to change, which will indeed then also affect the ...

2018年6月25日 · I'm looking for information regarding TLS/SSL cipher suites strength. for example, when pressing F12 on chrome, there is a security overview tab with cipher protocol and suites information. Chrome Security Tab example: Now I'm interesting on how do I know which cipher suite consider STRONG or WEAK. Is it the key strength? the algorithm?