安全協(xié)議與標(biāo)準(zhǔn)10-wlan和gsm3g安全-免費(fèi)閱讀
【正文】 2023年 1月 25日星期三 下午 9時(shí) 48分 31秒 21:48: ? 1最具挑戰(zhàn)性的挑戰(zhàn)莫過于提升自我。 2023年 1月 25日星期三 9時(shí) 48分 31秒 21:48:3125 January 2023 ? 1空山新雨后，天氣晚來秋。 , January 25, 2023 ? 很多事情努力了未必有結(jié)果，但是不努力卻什么改變也沒有。 :48:3121:48Jan2325Jan23 ? 1故人江海別，幾度隔山川。 ? 越獄后，可以透過如 Cydia這一類包管理器，來安裝 App Store以外的擴(kuò)展軟件及外觀主題，或是完成越獄前無可能進(jìn)行的動作，如安裝 Linux系統(tǒng)。 A5/2 is weaker and used in other countries. ? Serious weaknesses have been found in both algorithms: it is possible to break A5/2 in realtime with a ciphertextonly attack, and … A5/1 to be broken with a rainbow table attack. ? The system supports multiple algorithms so operators may replace that cipher with a stronger one. A5/1 / A5/2 ? A5/1 is used in Europe and the United States. A5/2 was a deliberate weakening of the algorithm for certain export regions. ? A5/1 was developed in 1987, when GSM was not yet considered for use outside Europe, and A5/2 was developed in 1989. ? Both were initially kept secret. However, the general design was leaked in 1994, and the algorithms were entirely reverse engineered in 1999 by Marc Briceno from a GSM telephone. A5/1 ? A5/1 is used in Europe and the United States. A5/2 ? A5/2 is a stream cipher used to provide voice privacy in the GSM cellular telephone protocol. ? The cipher is based around a bination of four linear feedback shift registers with irregular clocking and a nonlinear biner. ? In 1999, Ian Goldberg and David A. Wagner cryptanalyzed A5/2 in the same month it was published, and showed that it was extremely weak — so much so that low end equipment can probably break it in real time. ? Since July 1, 2023, the GSMA (GSM Association) mandated that GSM Mobile Phones will not support the A5/2 Cipher any longer, due to its weakness, and the fact that A5/1 is deemed mandatory by the 3GPP association. KASUMI（ A5/3） ? KASUMI algorithm is specified in a 3GPP technical specification, used in UMTS, GSM, and GPRS mobile munications systems. ? KASUMI is a block cipher with 128bit key and 64bit input and output. – Core of the KASUMI is an eightround Feistel work. – The round functions in the main Feistel work are irreversible Feistellike work transformations. – In each round the round function uses a round key which consists of eight 16bit sub keys derived from the original 128bit key using a fixed key schedule. ? In UMTS KASUMI is used in the confidentiality (f8) and integrity algorithms (f9) with names UEA1 and UIA1, respectively. ? In GSM KASUMI is used in the A5/3 key stream generator and in GPRS in the GEA3 key stream generator. A3/A8 ? Most GSM providers use a version of COMP128 for both the A3 authentication algorithm and the A8 key generation algorithm. ? … which shows a method by which COMP128 can be broken in less than a minute. ? GSM work operators are slowly migrating from COMP128 (also known as COMP1281) to COMP1282 or COMP1283. COMP128算法 ? Basic functionality Input – 16 Byte random value (challenge) – 16 Byte secret key of the mobile station Output: 12 byte – 32 bit used for authentication – 54 + 10 bit used for A5 initialization UMTS ? The Universal Mobil
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