Mohona Ghosh

Learn More
Mobile-based branchless banking has become a key mechanism for enabling financial inclusion in the developing world. A key component of all branchless banking systems is a mechanism to provide receipts to users after each transaction as evidence for successful transaction completion. In this paper, we present results from a field study that explores user(More)
In CRYPTO’16, a new family of tweakable lightweight block ciphers SKINNY was introduced. Denoting the variants of SKINNY as SKINNY-n-t, where n represents the block size and t represents the tweakey length, the design specifies t ∈ {n, 2n, 3n}. In this work, we evaluate the security of SKINNY against differential cryptanalysis in the related-tweakey model.(More)
The Kalyna block cipher has recently been established as the Ukranian encryption standard in June, 2015. It was selected in a Ukrainian National Public Cryptographic Competition running from 2007 to 2010. Kalyna supports block sizes and key lengths of 128, 256 and 512 bits. Denoting the variants of Kalyna as Kalyna-b/k, where b denotes the block size and k(More)
Abstract. Biclique cryptanalysis is a recent technique that has been successfully applied to AES resulting in key recovery faster than brute force. However, a major hurdle in carrying out biclique cryptanalysis on AES is that it requires very high data complexity. This naturally warrants questions over the practical feasibility of implementing biclique(More)
In this work, we revisit the security analysis of AES-128 instantiated hash modes. We use biclique cryptanalysis technique as our basis for the attack. The traditional biclique approach used for key recovery in AES (and preimage search in AES based compression function) cannot be applied directly to hash function settings due to restrictions imposed on(More)
In this work, we apply the sliced biclique cryptanalysis technique to show 8-round collision attack on a hash function H based on 4-branch, Type-2 Generalized Feistel Network (Type-2 GFN). This attack is generic and works on 4-branch, Type-2 GFN with any parameters including the block size, type of round function, the number of S-boxes in each round and the(More)
In CRYPTO’16, a new family of tweakable lightweight block ciphers SKINNY was introduced. Denoting the variants of SKINNY as SKINNY-n-t, where n represents the block size and t represents the tweakey length, the design specifies t ∈ {n, 2n, 3n}. In this work, we evaluate the security of SKINNY against differential cryptanalysis in the related-tweakey model.(More)
  • 1