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I need an implementation of AES(Rijndael) in java that allows use of a 320-bit key.

Please suggest a reliable implementation

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AES does not include 320 bits as one of the key lengths in its specification. – Jonathan Garber Feb 8 at 14:41
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Key derivation function. – Thomas Feb 8 at 14:42
@JonathanGarber ok.. Do you know of a non standard implementation of AES that allows 320bit key.. – userSeven7s Feb 8 at 14:43
Why do you want 320 bit keys? 256 is already more than enough. If it's because your key material is that large, just hash it with SHA-256 to get a 256 bit key. – CodesInChaos Feb 8 at 14:58
If it's "nonstandard", it's not AES. Precisely why do you need AES with a 320 bit keys? Why won't a key derivation function followed by a standard AES be appropriate? Why won't another cipher that takes 320 bit keys be appropriate? – poncho Feb 8 at 14:59
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closed as off topic by CodesInChaos, mikeazo♦ Feb 8 at 15:21

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1 Answer

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AES only comes in variations with key sizes of 128, 192 or 256 bits. If your issue is that the key you want to use is 320 bits, you can use a key derivation algorithm such as PBKDF2 to transform your secret into a key with a valid length.

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If you got a key with 320 bits of entropy then you would not need a PBKDF, but a KBKDF, e.g. one of those outlined in SP 800-108 or HKDF. Using PBKDF2 would not be efficient, as it has been designed to be slow. – owlstead Feb 9 at 1:47

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